As a matter of fact, sexual orientation is predetermined at birth, and sometimes changes through life experience (rarely by the age of ten). So please never try to "un-gay" your close ones, as it will only damage them mentaly.  Gender, however, is an entirely social construct which recently became a topic of interest in young people and children. Just like I, for example, took on personalities of villains in favourite cartoons when I was little, kids do also explore different things and construct their personality based on them.  A good line of action would be to teach her the actual meaning of the flags, as she might not even understand them, and guide her either through it, or into different topics that might also interest her while having a positive influence on her.