11 year olds question?

im sorry but i need an answer. every single 10 and 11 year old i know is obsessed with their period!!! they always talk about that they think their bout to srart theirs for the first time when they are like not even developed at ALL yet!!! and their obssessed about wearing makeup and like i never cared! im 14 abd when i was 11 i always played with dolls and polly pockets lol [i had a whole collection] and i never talked about my period abd when im gonna get it for the first time and watever... And they always act older than wat they are! last year i had a bathing suit i couldnt wear anymore so i gave it to my 11 year old cousin and i didnt fit her at all like too big but this year she had to getca new bathing suit claming that her boobs popped out of it and she has none!! like flat as a board!! she is like the same size as she was last year!! soo is it just me or is they growing up too fast? im soo stupid lol but no rude coments plz so ummm thanks <3