What is the translation leaving out, i.e., what is “sich lassen” doing?
The Germans often use “lassen” (let) where in English we might say “get”.
Ich lasse mein Auto reparieren = I’m getting my car repaired (literally “I’m letting my car repaired”)
Ich lasse mir die Haare schneiden = I’m getting my hair cut (literally “I’m letting my hair cut”)
You didn’t include the English translation of this German sentence, but I’m guessing it’s something like “she’s getting divorced from her husband”, or perhaps “she got divorced from her husband”, since “ließ” looks like past tense.
“lassen” is used when you don’t do it yourself but “let” someone else do it for you.
I think english also can use “have” for this:
Oh das Fenster ist kaputt! Ich werde es morgen reparieren lassen.
Oh the window is broken! I’ll have it repaired tomorrow.
Repairing a car and cutting hair are good examples, because you rarely do it yourself.
Getting divorced also falls into this category. You can’t divorce yourself. You need to go to the Scheidungsrichter/Scheidungsgericht and they will divorce you.
Ah yes, thank you, “having” can have the same meaning:
I’m getting my car repaired = I’m having my car repaired = ich lasse mein Auto reparieren
The “getting” or “having” in English implies the same as in German, that it’s someone else who’s going to be doing the actual work. But “having” doesn’t always work in English. “She’s getting divorced from her husband” is fine, but it would be very odd to say “She’s having herself divorced from her husband”, which I think is the literal translation of this clozemaster sentence. “Getting” can work in cases where “having” sounds odd, but they both translate to “lassen” in German.