Not childish, but outdated.
No not at all. I currently have a similar bedset right now too and I'm way over 20 lol.
I am turning 20 in November and I've had this bedding set since I was about 17, its still not opened. I have been obsessed with zebra print since I was like 15. I am redoing my room in a few weeks, with this bed set I wanted to do two walls light pink and 2 walls dark pink with black drapes. I don't know if I should stick to this bedding or go for something a little more modern-like. Be honest is this bed set too childish for a soon to be 20 year old?
Please be honest because once I redo my room, I am stuck with it till I move out with my boyfriend in a few years.