I know guppies are bad with males, but I'm not sure about females. Neon tetras have been known to tail nip, but I don't think that would be a problem with a female though. Tetras have to be kept in schools of 6-10, so they would be a little crowded in a 10 gallon.
Here's a site that might help you in choosing a companion. http://www.oneworldinternetcafe.com/...ompatable.html
It doesn't say cage or group requirements, but it gives you an idea of what is compatible.