Your business = your rules
Her child = her choice
I'd let her know that your program is obviously no longer able to meet her needs so she needs to submit writtten notice of withdrawal according to you handbook/policies.
As a business owner I get to decide what services I offer
As a parent their only option is to decide if those policies work for them or not.
Don't change your routine for her.
She doesn't go to McDonalds and try to negotiate them selling her a Whopper
