Re: my sister...
dont turn her into ur parents. maybe she wasnt looking at girls for her sexual pleasure, maybe she's just curious. around 10 is when people start having Sex Ed in school so maybe she was just curious about when a womans body would look like after puberty (porn is a bad example of this....but its something). if ur real concerned, talk to her. if u feal its that bad then deal with it urself, dont leave it to ur parents if u feel something's tat bad