I would at least return the call or email and tell her your hours of operation. If she actually works within those hours, perhaps you can schedule an interview. If she is in fact needing care for 11.5 hours per day, she probably needs to look elsewhere.
I won't work for families for more than 10 hours per day. That gives them an 8 hour work day, an hour for lunch and a half hour to get back and forth each way.
