It sounds like your friend's cat, Lisa, has given birth to three kittens. You can congratulate your friend on the arrival of the three adorable kittens. Here's a suggestion for a congratulatory message: "Congratulations on the arrival of your three adorable kittens! They must be so cute! Wishing you and the little ones all the best!" If you want it in German, here's a translation: "Herzlichen Glückwunsch zu den drei süßen Kätzchen! Sie müssen so niedlich sein! Ich wünsche dir und den Kleinen alles Gute!"