[Trouble with Cat in Nursery]

I have a 12 week old daughter and two cats. My daughter recently began sleeping all night in her room, whereas before she was in a bassinet in my room. I put a baby gate up in the doorway to her room to keep the cats out. It worked well for one cat while the other is constantly jumping over it to get in her room. I woke up this morning because I heard her mobile playing. The cat was climbing all over her crib. He had knocked the mobile sideways almost falling on her head, pulled down the decorative blanket that had been draped across the headboard of the crib, and knocked a wooden letter that had been hanging on the wall into the crib. Luckily it did not actually land on her. I had been tolerating him just going in there and wandering around but I cannot have him putting the baby at risk of getting hurt. If I cannot solve this problem in the next day I am going to have to get rid of him which I would really rather not do. I do not want to keep her door closed all of the time. Is there a different kind of gate i could get or something I could attach to the existing gate? Please help as I am an animal lover but of course put my childs well-being first.