But don't you wonder what inhibits them that didn't inhibit us? Again, I'm all for evolution. But science has a lot of mysteries. To me, this is one of them. If it isn't a mystery to someone else, please educate me.

Yeah. I understand the environment has a lot to do with it, how it influences evolution, but it's a question I don't think was answered in the biology classes that I have taken so far. Well, only one actually dealt with issues that this question would pertain to, the rest was microbiology and even genetics didn't quite delve into apes too often.
She asked a good question, but it couldn't serve as proof against evolution.
I can't tell you much as I'm fairly ignorant on the subject but one part of evolution that a lot of people seem to misunderstood is how animals 'adapt'. It's not as if giraffes needed to reach the leaves and then evolved to have longer necks, rather the ones with necks long enough didn't die and were able to reproduce. If the entire world flooded we wouldn't just develop flippers or gills if we waited long enough.