Should I pay her?

Husband and I are moving into a new house. The house is close to MILs house. MIL cleans houses for a living. She said if I buy the correct cleaning supplies she will come clean our house twice a month. She sounded like she really wanted to do it. I said great! Husband says we have to pay her to clean our house, but she said nothing about payment. I would rather clean our house myself instead of paying for her to do it. What should I do? What is an average payment for a bimonthly maid?