Your friend is talking about Lisa's cat giving birth to kittens. The word "Junge" in this context refers to offspring, and the number specified is three. So, Lisa's cat had three kittens. In English, the message can be translated to: "Oh my god! Did you see what Lisa shared on Insta? Her cat had 3 kittens - they look sooo cute. I want a cat too :(((." You can congratulate your friend on her new kittens by saying something like: "Wow, that's great news! Congratulations on the three adorable kittens. I'm sure Lisa and the cat must be so proud."