Well they never went and adopted Meeko without you bringing him home, you can I think only bring one dog home for them, the other pet one of the children will bring home and it will not be a dog.
I brought Meeko to them and one of the cildren adopted him right away.
If they did not want a second dog, they should come up with a mudcrab or something, but in dozens of hours happened nothing.
I am pretty sure both children can adopt a pet, so two pets.
I would prefer Meeko and a Husky tough. :/