Tips on how to prepare 3 year old for first sleepover?

❤🐢 • Mommy of two beautiful little girls 💜

My 3 year old is going for her first sleepover in a couple weeks at her aunts house. She’s never stayed with anyone overnight before but has gone to peoples houses a bunch of times for a few hours at a time without us during the day. We’ve never needed anyone to take her overnight before but I’m having a baby in a couple months so we need someone to watch her while we’re at the hospital. We are doing a trial run in a couple weeks but when we told her about her sleeping over at her aunts house she got all serious and was like “no, I sleep upstairs in my bed.” So we tried to tell her how fun sleepovers are and how she’ll get to go and play with all her cousins toys and then she’ll go to bed there in their spare room and stuff and she just says “no I sleep at our house” or “I sleep at the white house” (our house is white lol) we keep trying to talk to her about it and make it sound fun but she seriously doesn’t want to go. I really want it to be a good experience for her and want it to go well so I don’t have to be stressed about it when I’m in labour. Any advice?