CT Lawyer, I’m sorry to say, but I think you may not realize what a different stratosphere you live in when it comes to money compared to many people who are here in the Coffee Room. Money is very often the defining point and a dog definitely does not need to be the priority of any frum Jewish family.
There are other animals that can teach children responsibility, including things like fish or birds. I am aware of the benefits that dogs do provide, especially to people like your MIL and other people as a form of animal therapy, but given the vast majority of chareidim who live in apartments, as you yourself said, there is little space for them in such quarters under normal circumstances, which is what we would be referring to.