http://www.peninsulahumanesociety.or...es/clinic.html

The humane society in San Mateo charges $70. The San Francisco SPCA charges $100. I'm sure you could arrange a payment plan if that is too much, or just start saving $10 every week for the next couple of months. You should never spay a female while they are in heat, because of blood loss. Just be sure she is in your sight at all times when she's not indoors, to prevent accidental breeding.