Babysitting with Grandma

There's a family here that I've gotten to know really well. Their son, Theo, is 2 now and has been at the preschool since he was 8 weeks old. I've had the privilege of being his teacher since he started all the way up until just recently. Along with taking care of him at school, I've been babysitting Theo almost just as long. Along with the usual babysitting, I've been called to come over for play dates with him (the dad was around the house but busy grading papers), and have been called over to be his transition piece when they moved to their new house. The mom is pregnant and yesterday the mom and dad went to the hospital because the mom was in labor. They had called me to ask my availability to come over to hang out, to play, to bring Theo to the hospital, or whatever was needed and I told them to feel free to call me anytime. The grandmother (who is staying with them to help with the new baby and Theo) called me mid morning to come over and play with Theo. Talk about awkward. Nothing was progressing at the hospital so the grandmother stayed home all day with me and Theo. The grandmother kept following us around and making comments about what we were doing, how I needed to change the activities so he would be worn out more, and when I was giving him a bath before bed, she came in telling me that the bath was taking too long and it was time for Theo to be put to bed. While I know she doesn't know how capable I am first hand, I know that the parents have told her that they trust me and that I've been taking care of Theo for a while now. I wonder if this is why people with children often don't live with their own parents.