Is it wrong for girls who wear the hijab to show their hair in front of girls who are homosexual? Would it be a big deal (as it becomes a sin) if they called me pretty and all those compliments?
The purpose of dress codes in Islam is to take sexuality out of public interactions so that men and women can interact without either sex having reason to sexually admire the other sex. Based on this, we can draw the analogy that it would be best if women wear the hijab in front of women who are likely to sexually admire them.
Also note that most scholars are of the opinion that Muslim women should wear the hijab before non-Muslim women, as discussed in this answer.