I brought my dog to my mom's house, where she was babysitting her friends 2 yr old daughter. The baby was sitting on a blanket, playing with tupperware and when my mom turned her back, my dog got as close to the baby as she could and PEED ON HER!!!!! ???? Was this a territorial thing to do or what??? My dog is a female lab, also around 2 yr old. Was she jealous? I am JUST SHOCKED!!!

Yes, dominance, territorial, keep the dog away when the child is on the floor, you say "turned your back" when you do, take the dog with you.
Dawn.

She was probably marking the baby as part of her pack!
:)
Edit: Another possibility is, if the baby's nappy was wet/dirty, the bitch felt the smell should be masked - bitches as well as dogs will wee on top of other dogs' wee. So make sure the baby has a clean nappy to avoid stressing the bitch.
:)