For a Mothers' Day Grouch

I received this email from my doggy, Xena, Warrior Lab Mix Breed Princess of all Norwalk, this morning:

Dear Mom:

Thank you for everything you do for me; food, walks, pets, and a safe place to live. 

I try to be good all the time but sometimes I can't help myself — and MP says that's OK.

I Love you,

Xena

What I want to know is, how did Xena know MP? Oh, I forgot, she corresponds with MP's doggies!