It is totally up to you & what you feel comfortable with.

Our son had his first sleep over at my IL's (who are just wonderful) at about 12mths & he was pretty good. He is now 4yrs old & goes at least once a fortnite for a sleepover due to mine & DH's work commitments.

But as I said it is totally your choice as to when you are comfortable for your daughter to spend a nite away from you. Another suggestion if you want to get some rest is maybe for her to go for an afternoon "play date" at your IL's & that still gives you time to rest while she is gone without her having to stay anywhere.