My parents adopted our dog before I was born, and were of course nervous about her reaction when they brought me, their first child, home.
Turns out, Penny was a natural mother. She would let me climb all over her just like this baby! Her protectiveness even got her in a lot of trouble. She fell into my aunt's pool when I was three because I was walking too close to the edge and she tried to walk in between me and the pool to keep me safe.
Dogs are awesome, aren't they?!