[details=“English Translation”]I work as a nurse.
[/details]
Is there a real difference between ‘Krankenpflegerin’ and ‘Krankenschwester’?
I do feel intuitively that ‘Krankenschwester’ sounds a bit outdated and sexist (just a little, since ‘Krankenbrüder’ doesn’t seem to be a thing and ‘Schwester’ brings a bit of religious connotation), but in day-to-day life do people just use ‘Krankenpflegerin’ and ‘Krankenschwester’ interchangeably?
According to the German Wikipedia page, the use of Krankenschwester and Krankenpfleger as professional titles are regulated by a 1957 law, and since then Krankenschwester is a legally protected professional title in Germany (second paragraph of the section Zur_Anrede_„Schwester“) -
Krankenpfleger – Wikipedia
The page does not mention Krankenpflegerin, and so this suggests that Krankenschwester is the official term for female nurses (and Krankenpfleger for male nurses).
Now for a bit of fun to test your hypothesis on whether it is a little outdated and sexist.
When these word comparisons come up I follow @morbrorper’s lead and use Google Ngrams, which shows the change in time of usage of a word or phrase in books.
For this one, I chose 1850 as the start date (emergence of nursing in Crimean War, Florence Nightingale, founding of L’Institut et Haute École de la Santé La Source etc.).
I compared Krankenpfleger, Krankenpflegerin and Krankenschwester and the result is here -
Google Ngram Viewer: Krankenpfleger,Krankenpflegerin,Krankenschwester
So in books, it appears that initially Krankenpfleger/in (combining both forms) was the preferred term, and then that changed just after the end of the second world war to be Krankenschwester. Since then, the dominance of Krankenschwester has increased, and today (well, in 2022 actually) it is about a 5 to 1 ratio in favour of Krankenschwester over Krankenpfleger/in in books.
With a ratio of 20 to 1 in favour of Krankenschwester over Krankenpflegerin, it certainly appears as though (in books) Krankenschwester is the preferred term for lady nurses.
As Google Ngrams looks at occurrences in books, I have no idea whether there is a difference in spoken German, hence we can now wait to see whether one of our wonderful German native speakers or experts can give us real insights into modern German usage, and any cultural aspects around whether Krankenschwester is seen as a little outdated and/or sexist.
P.S.
As an aside, I checked the WHO report on gender ratios in nursing.
Nursing personnel by sex (%)
As can be seen, the current ratio of female to male nurses in Germany is 5 to 1 (and in Austria it is about 6 to 1). The combination of Krankenschwester/Krankenpflegerin versus Krankenpfleger in the Ngrams results is between 6 to 1 and 7 to 1. Hence, there is a reasonable correlation between the gender ratio in nursing in the two main German speaking countries and the occurrence of gendered terminology in books.
At least in political correctness terms, your assumption is pretty much correct.
This is part of a much bigger debate in German language about having more gender neutral words for humans (especially for job titles). Many job titles who were originally grammatically male only, but referred to both genders are nowadays viewed by some/many as if the gender is not only grammatically and a female form for the job title was also created. And even further than that there is the attempt to create gender unspecific job titles, using some special plural forms.
For example, “Studierende” instead of “Student” and “Studentin”, “Lehrende” or “Lehrkräfte” instead of “Lehrer” or Lehrerin".
Practically speaking those are hard to enforce, though, and especially older people have a large resistance to changing the way they speak (especially by force). This does not only apply to those “gender reforms”. The reason I mention this might also explain the stats zzcguns looked up. In general many people might still use the old expressions more. Younger people who grow up with the new terms might have less resistance.
In general “Krankenschwester” is a even more egregious example because it implies the job is only for women/something men aren’t supposed to do/something beneath men etc., so it would be even more likely to be avoided in theory. Same goes for “Putzfrau” instead of “Reinigungsfachkraft” or something along those lines. Another male focused title would be “Feuerwehrmann”, implying this would be only a job for males (which it might have been in the past, I do not know).
This is still a very debated ongoing change in the German language, so it’s hard to predict how it will end up. I guess in the end, as a learner it’s annoying since you have to learn more terms to mean the same.
Personally, I’d advise if you use them actively to use the new terms, but some Germans might get offended by the notion of those new terms (and vice-versa some others by the use of the old term). In the end it’s a lose-lose situation 
In general there is also often not a unity yet which new term to use or how to do expressions in writing when addressing both genders with different job terms.
I hope this will get standardized at some point in the future, but we are still far away from that.
[details=“English Translation”]I work as a nurse.
[/details]
Thank you @zzcguns and @Aki-kun for the amazing analyses–you are the reason why I love Clozemaster.
@zzcguns: I certainly came to my conclusion that ‘Krankenschwester’ felt sexist and oudated based on pure intuition (as I explained) and you proved me wrong for the ‘outdated’ part. I did not realise a) more females are entering the career of being a nurse and 2) ‘Krankenpflegerin’ is not a thing anymore based on usage statistics. What I do find interesting is why people are okay with using ‘Krankenpfleger’ and ‘Krankenschwester’ side by side, since it seems a bit inconsistent to me where most other professions (correct me if I am wrong) uses er:erin. My starting hypothesis to that question is maybe in Austria and Germany, due to the fact (which you provided) that females are the predominant gender of nurses, people prefer a term which ‘defaults’ to females, and thus ‘Krankenpflegerin’ (which sounds like, and is, a conjugation of ‘Krankenpfleger’) seems off. Don’t know if that is true, though.
@Aki-kun: I am aware of this wider debate on gender-neutral terms. Coming into German the first thing that stood out to me is the use of er:erin in daily writing–seems a bit too unnecessarily complicated to me, coming from English. And I agree completely with you on the feelings towards ‘Krankenschwester’ and ‘Putzfrau’.
I think on the greater point of job statistics, from my own anecdotal point of view, a lot of it comes down as some stereotypes of jobs mostly/only done by a certain gender only grow out slowly over time, both in terms on if they get employed or if they even chose the path of that job opportunity.
For example, when I went to school here in Germany, the ratio of female students who took science/math classes in high school was like 1/15 compared to male which might be even further disparage when it comes to university/college/higher degrees. Similar thing I can think of are certain sports or the military.
Likewise many small child education/raising jobs are still predominantly done by females. Or even the fact of the men working while the women raises the children and stays at home (for example the term “die Hausfrau” is widely used, while “der Hausmann” is a very new term most people wouldn’t even use [yet]).
It will probably take a few generations until the gender ratio in such jobs becomes more even.
And this also indirectly effects how we use the language around occupations (or you might also be able to argue its also the other way because we use those words that it strengthens certain job stereotypes).
