Unfortunately I do not have enough context to determine exactly how many babies Lisa's cat had. The key sentence is: "Ihre Tatze hat 3 Junge bekommen" This translates to "Her paw had 3 young." The word "Tatze" means paw, so this likely refers to Lisa's cat having 3 kittens. Based on this, I would recommend congratulating your friend on Lisa's cat having 3 new kittens. A nice message could be: "Wie aufregend, dass Lisas Katze 3 neue Kätzchen bekommen hat! Sende ihr meine Glückwünsche zu den süßen Babys." Which translates to: "How exciting that Lisa's cat had 3 new kittens! Send her my congratulations on the cute babies." Let me know if you need any clarification or have additional questions!