Note - I checked with the “Explain” feature, and ChatGPT suggests that verknarrt is a made up word and that verknallt was probably intended.
The German sentence “Sie ist in ihren neuen Welpen verknarrt.” can be a bit tricky because it contains a made-up or rarely used word “verknarrt,” which is not standard German. For the purpose of grammar and understanding, let’s assume the intention was to use “verknallt” (infatuated).
I’ve never heard the word “verknarrt”. Although you can never be entirely sure with slang and new words that teenagers make up, I don’t think this word exists.
I would not use verknallt for animals, it’s slang for being in love with humans mostly. Vernarrt is a thing though that you use as being passionate with animals or objects. It stems from Narr - jester.
I’ve updated the bug submission, including a link to this discussion (and a note to also update the Explain feature which was unable to see the nuance and hence chose “verknallt”).
Now that you have mentioned the word vernarrt I recall having seen it before as the cloze word in a sentence about a car - “Er ist so vernarrt in sein neues Auto, dass er jeden Sonntag damit fährt” (which is a translation from the English sentence “He is so crazy about his new car that he goes driving every Sunday” - here is the Tatoeba sentence for reference).