Anonymous
Some nannies in the DC area earn 25. for one child. All depends on how high or low your standards are.
There is no correlation between nanny quality and rate. You can get a great nanny for $12/hr and a lousy one for $18/hr. OP, just decide on the rate you are willing to pay and proceed. There are many, many more nannies than jobs and you will find a good one if you offer a fair market rate.
As others have noted $9-10/hr is a good rate in a share with a new nanny.