I've been struggling with raising one of my actresses sex appeal. Shes stuck at level 3/3 and I don't remember how to raise it. Could someone please tell me? Thanks in advance.

Second number shows the max sexappeal of your girl. In your case you can't get better than 3. I would suggest getting a better one. When you recruit a 12/60, you can pimp her until 60/60 via gym (4*15= 60, but random change, which leads to daily workout) or SPA (max 40, but then for good).