It seems like your friend is excited about Lisa's cat, which has given birth to 3 kittens. You can congratulate your friend by saying something like: "Congratulations on Lisa's new kittens! They sound adorable. It's no wonder you want a kitten of your own." In German, you could say: "Herzlichen Glückwunsch zu Lisas neuen Kätzchen! Sie klingen so niedlich. Kein Wunder, dass du auch ein Kätzchen wollen würdest." I hope this helps! Let me know if you have any other questions.