Hi Julie
Welcome aboard!
Annabelle's reply came in just as I was in mid-reply. I basically agree with everything she says.
Read our review of the Rex Turtle Beach. If you go there with an open mind and don't expect 5-star catering then you'll have a brilliant time.
The seas are normally calmer at this time of the year, so its wrong to say that the sea there WILL be too rough. I've seen tons of children swimming there, even in the higher seas at the start of the year. You could be pleasantly surprised.
Despite being the rainy season, you're sure to get lots of sun and come back with a tan. It rains most at night and in short, sharp showers.
Yes, some people get bitten to death in tropical beach resorts - others never get a bite. Follow the advice given in our Miscellaneous/Health & Safety articles and you stand a damn good chance of being one of the latter group.
Believe you me, if it was a dire as you seem to picture it, you certainly wouldn't get so many people falling in love with the island and returning year after year. So, go with an open mind and you'll have a fantastic time.
Let us know how you get on and have a great time.