Your friend is talking about Lisa's pets, not babies. Based on her message, Lisa has a cat (tatze is German for "paw" or "claw," but in this context, I assume it means she's talking about her cat) and that cat has had 3 kittens. So, no babies! If you want to congratulate your friend, you could simply ask her if she's had kittens and if she's letting her show them off anytime soon.