yup, 11 is pretty good (you should have bought a lottery ticket), she normally hits that edge around 6-7, and the last time I took someone to 12 there wasn't even a notification that anything had been accomplished, she just fell to her knees and game won, So I've no idea if it is worth anything or not, it might be that the swimsuit was unlocked in a previous version or it isn't there anymore, (I think v0.16 ot v0.15 only required 10 and that was cumulative ie if you played 5 games and got 2 in each you still won).
Last time I only won by using cheat engine to change some values around.
You should have unlocked the massage scene with 11 though right? that's the main thing, it mean you can unlock her apartment and the massage Job, if you don't have that yet, go back to the beach and look for her near the lifeguard station, she should ask if you can come to her home and give her massages
