Does she come weekly?
Housekeeping costs, like daycare costs, are going to vary from region. You'd be better off asking local friends what the going rate is.
Here's an average to go by:
In a larger metropolitan area, for a medium-sized apartment or house, plan on paying at least $100 for cleaning twice a month.
In less populated cities or towns, for an average-sized house (2500 square feet), around $75 is a typical fee.
For a large national chain, monthly cleaning service in a three-bedroom, two-bathroom home, runs around $175 per cleaning.