Mel, I think a female should be fine with your rainbows, but keep an eye on it. I have females in with lots of other fish...males don't cohabit well, but the females are okay as long as their tanksmates aren't going to eat her, or be HER food.

Tiffany, you are doing a great job. It does take time to grow back, and sometimes they grow back funny, but Elija will heal. Good work.