The only pet sim I've played that allowed for multiple accounts was WolfPlay, but you could have a max of three total accounts per household AND the accounts could not benefit one another in any manner, including buying/selling items, gifting, etc.

I am also always puzzled by people who claim that FR is the exception, not the norm, when it comes to allowing for multiple accounts... though I tend to assume that it's a way to try and get sympathy because they couldn't bother to read the rules.