Did I overreact??

So today my mom was watching my son while I was at work. And I knew they were going to the airport to pick up my sister in law and then she was coming or so I thought. But then they went to my grandfathers house and at this point I thought they were on their way home. So I got frustrated that I had no clue where my 1 1/2 year old was. And I already did not want him over at my grandfathers house. But Now my mom said I hurt her feelings because I don't trust her with my son. Which is never what I said, I just simply ask that I know where my child is at all times what if something happens and I have no idea? I feel like I had every right to be frustrated.