Two thumbs up for spaying!
It's healthy for them and easier on you and leaves no wiggle room for accidental litters or furniture staining!
I would spay her before her first heat though since there is now proof that doing so prevents the chance of breast cancer and the earlier you have her spayed the easier it will be on her since pups recover faster than adults.
Call around and ask numerous vets about their opinions on spaying and neutering and ask why they believe what they believe. Some 'old science' vets still say that letting a dog/cat complete a heat cycle is the right way to go about it but 'new science' vets have proven that is wrong and that there are definately better alternatives.