I have double babies. I'm going to make a new group for them. All I'll be using is this scene forever, so you can frequently check if there's updates. The steps to claim/adopt one is this:
1: see a pet you might want
2: if there's multiple of it, check the group for which you'd like
3: to claim one, ask in a reply including it's name. I will most likely say yes, unless that pet is already claimed. if you claim, I will give it to you when it's fully grown.
4: if you want to adopt it straight away, it'll cost something. All I need is 1 Chicken doller or a wish list pet/item
have fun and enjoy!