She would love all of them because Eric had Max that Ariel maybe helped taking care of! But I think she's a person who wouldn't like to take walks with the dog, a cat would be better for her since cats are oftenly very independant, but also fish since they don't require a lot of care, just clean the aqurium a little now and then and feed them everyday!

But fish don't do much...

She'd have tanks full of exotic fish, and she can still talk to them. (Remember human Ariel could communicate with fish) <-- You could use that as a subplot or even a plot in your fanfic, using that human Ariel in out time can talk to fish.

duh!

Cuz she's connected with them! She is a mermaid!