What is the decisive characteristic for you that the youth room decides from the children's room?
Is my room a youth or children's room? There are:
Bed 1.20m with pull-out possibility for friends… (then 2 beds) with 1 bedside table
3 shelves for writing and school supplies, books, CDs, DVDs…
2 wardrobes
1 beanbag
1 desk with laptop
1 purple wall with fairy lights (pictures of friends hanging on it), 2 posters
It is 20 square meters.
So, a children's room mostly contains toys (very many).
Your room sounds like a youth room. So be calm.
There are posters of Disney characters in the children's room and bare-breasted women in the youth room.
Well desk and bed., Bookshelf and wardrobe, more boxes for underwear and toys, bedside table maybe. Also TV or couch
In terms of furniture, it sounds like a youth room.
I think the decorative items, wall hanging fabrics (bedding and curtains), room lamp / floor lamp differ.