I suspect part of the problem might be that LW believes (or believed 5 years ago) that all dogs are more or less the same, so "kid said she wanted a dog" was enough to convince her the kid agreed to any dog. And I have absolutely seen people double down on their biological kids or spouses or parents.* "But you SAID you wanted a dog! We made a commitment to a poor helpless animal based on what you said."
no subject