It seems like your friend is talking about a cat (Katze) that had kittens (Junge). "Tatze" is a colloquial term in German that means "cat" or "kitty". So, according to the message, there are 3 little kittens! However, if you're looking to congratulate your friend on her own babies, it seems like she doesn't have any human babies, but rather is expressing a desire to have a cat of her own. If you want to respond, you could say something like: "Aww, das sind ja wirklich süße Kätzchen! Vielleicht bekommst du ja auch bald deine eigene Katze" ("Aww, those are really cute kittens! Maybe you'll get your own cat soon!")