I've always been under the impression that it is best to spay the girls right at the six month date. That's what I have done. I had one Siamese cat that I waited for two years before spaying. She lived to be 21. Go figure. I think doggies run about the same, spaying wise.

I would stay on the side of caution and have her spayed soon, before she escapes and makes little ones!

Good luck. Spaying usually runs smoothly.