Tell me about. . . caring for fish.

[big D]

Its unlikely that she has a female betta because they aren't as nicely colored and they have short fins. I think all of the ones you see in the store are typically males.

For a small tank, if you're not interested in anything sophisticated, an Eclipse tank is def. the way to go. As a starting small tank I think your best bet is a 10 gallon glass tank and one of these eclipse hoods

http://www.amazon.com/Eclipse-Lighti.../dp/B0002APZU8
I know the eclipse tank is more expensive than getting a tank, filter, and cheap light, but you'll wind up with a much nicer looking tank when its done instead of wires and crap hanging all over the place.