I am looking to go back to working days full time. I currently work nights so i can be with my daugther during?

the day. Im currently looking for a babysitter. My mother in law is available but she is a total bum. She doesnt watch our kids unless we pay her, shes always putting her two cents in about my stepson who is 6. Shes helped raise him since he was a baby and ever since shes been up his *** always telling us how to dress him and what to do. I also have a 20 month old daughter that she never criticizes us about. I think she thinks we treat her better but their the same. Anyway, shes upset that im looking for someone else to watch them this summer and she even made the comment "well il just come pick up colin" (which is my stepson) every day if i have to . I don't really let her take my daughter alot of places. Anyway, am i wrong for not letting her watch them? She does not have a reliable car, she has no cell phone, and shes rude to me most of the time when I constantly try and be nice. I just don't want to deal with her everyday and I don't feel my daughter is safe with her driving.