Unfortunately I don't 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 doesn't make literal sense when referring to a cat having babies. It seems there may be a typo or some missing context here. Based on the sentence structure, it sounds like the intention was to say Lisa's cat had 3 babies/kittens. But without more context I can't say that definitively. To be safe, I would recommend congratulating your friend on the new kittens and asking her exactly how many there are before stating a specific number. Or you could say something general like "Congratulations to Lisa on the new additions!"