Well you don't have ! to get her a mate, she will do just fine with you on her own, but if you want another bird anyway go right ahead

, especially if you don't mind that you could end up with two females, or two males if she infact turns out to be male.
There are many breeders that ship. Not sure where to begin looking, others may have sites you could visit. I myself look alot on
http://www.petlink.com.au. I think I remember seeing that alot of people would only ship around Australia though.
When you get another bird, keep it in quarantine for the 30 - 90 days and when you integrate them, do it slowly. Leave the new bird in the cage you have for it and bring your baby with you to sit near the cage and just talk to the new bird with you. Do this for a while, then introduce the cage to your babies area and let her get use to it being there. Eventually you can let them have supervised play together.
Remember, girls can be rather viscious, even to a potential mate. Breeding season is a very dangerous time for males

. Then again you could have "love at first" sight like my Mickey and Kai. Mickey follows kai like a little lost puppy dog, she relies on him for everything and he protects her and cares for her. Or it might be friends from the beginning.
Just remember its alot busier having two birds + . It takes up way more of your time.

I know all about that, as do most of us here.