I know the feeling. Maybe though she wants to feel that she has at leadt been considered to babysit. Have you tried asking her to babysit at a time that you know she will be very unavailable to do so and just pretend that you "'forgot" about her prior engagement? That way you asked and she can't complain that she never gets to look after them because you can just say well I did ask but you refused. I agree with you though. If you are not comfortable with her looking after them, then she shouldn't look after them. It's not worth the time spent worrying about them when they are with her, and children are not playthings to be lent out to make someone happy.