We first took her at 9 months, then again at 11 months.
Both times we stayed away from the big rides - Even if they did not have a height min we left them out. I just didnt trust that she would be 100% safe (being so small) and I did not want to scare her.
We took her on the lazy river, in the large main pools, and in the childrens play area. If I am remembering correctly then the kids area at Typhoon lagoon was better than BB.
We arrived early to get a shady spot. Each time we tried to get a spot with sand as she loved digging and playing in it.
Also you can take cooler bags into the park, so if your dd is still using bottles you can keep them cool - we also took lots of bottles of water for us.
Hope this helps you - I think if your dd likes water then you will all have a amazing time, we got some brilliant pics!