Juvenile rams will readily pair if you have a male and female present, but often if a male and female pair has formed and for instance the male dies, the female might not take another mate. I had this exact situation happen to me and I got her a new male from the LFS. Either she decided she wasn't into younger men or she just decided that she liked girls, but she wanted nothing to do with him and she would constantly chase him away even when he was passing by. I've also had pairs swap partners before. Not sure what is in my water.......