Based on the message you provided, it appears your friend is talking about Lisa, who shared on Instagram that her cat (referenced as "Tatze" in German) gave birth to 3 kittens. So, in this context, there are 3 new baby kittens. You could congratulate your friend by saying something like: "Herzlichen Glückwunsch zu den süßen neuen Katzenbabys von Lisa! Sie sehen wirklich bezaubernd aus!" (English translation: "Congratulations on Lisa's adorable new kitten babies! They look absolutely enchanting!")