"Lana, I'm sorry if I mislead you. The truth is we are just not pet people and have zero interest in acquiring a four legged family member. You know better than anyone else how unfair it is to an animal not to be with people who really want it. On that note, please don't suggest such a thing to little SGL again. It's mean to get his hopes up when our answer is always going to be 'no'."
And if, for some wild reason, she actually shows up with a puppy/kitten, I give you my permission (whatever that's worth) to get good and mad. As in, "What the (not E)hell is wrong with you??!!!?? We told you we didn't want a pet. Do your [bosses] at [shelter] know you pull these kinds of stunts?!?!?!" mad.