Yes, if they don't put in the same amount of work it makes sense that one would progress faster than the other. With that in mind, it interesting that whatever slight differences in environment the two girls have been subjected to growing resulted in different interests. Or it could perhaps be the desire to be seen as different in the eyes of the their parents drove one to choose a different set of interests. Who knows...
Agreed. Lots of variables involved. One thing I know for sure...dad is on the edge of a psychotic episode constantly. 4 teenage girls - 14 and 15 years old.