An average is just an average. Ring round the vets in your area to find out how much it will cost you. Also ask when they are willing to spay her - some will not do it until she has weaned her kittens, at 10 weeks or so.
Don't let her out, she can get pregnant again very quickly and you also can't afford for her to not come back leaving you with tiny dependant kittens.
I've seen prices between $45 and $250, it really all depends on your vets and your area. You can also google low cost clinics, their may be one near you.
The vet I just took a cat to last week was $90, then costs for the medications and iv's. But I'm sure it varies everywhere. Love the pictures and I'm so glad she's being a great mama!
Oh goodness! I just called my nearest vet and they wanted over $300!!! That is absolutely insane!! I have many animals and $300 will buy a lot of feed, I just cannot afford that for a spay.
The next closest vets are over 4 hours one direction, but one is a low cost spay/neuter clinic. I guess I'll have to go with that.