We went to Centara Grand when our kids were similar ages – 11, 9 and 6 – and it was perfect for us at the time. We were in a two-bedroom beach villa, which had a double bed on the mezzanine and a twin room downstairs for the younger two; DS1 (11 at the time) slept on a sofa bed in the living area.
There was a kids' club and also a teen zone with table tennis, etc. One of the reasons we picked CG was that they didn't have jet skis or any other motorised watersports (this was 6 yrs ago, might be different now), but there was good provision of non-motorised watersports. There were also various organised activities suitable for older kids + pre-teens. I remember the house reef being v. good for snorkelling, and the diving centre was great too. It's a Thai-owned resort so unsurprisingly the spa was lovely! Food was good too, with a Thai restaurant as well as an overwater Italian restaurant, which provided a bit of variety in terms of menu and setting.
Then we stayed in a villa at Amilla Fushi this year, which was next level in terms of facilities, service – and budget! A very special place, and we all absolutely loved it.
We booked Amilla through a small, specialist operator who were excellent at advising on options to suit our requirements. The resort itself was their suggestion, when another option (The Hideaway) fell through, and when we had to postpone from last year due to Covid they managed everything brilliantly. We would normally book flights/accommodation etc. ourselves, and I had already done loads of research (keeping notes via a geekily detailed spreadsheet, which I will refer back to if we're ever lucky enough to get the chance to go back!) – but in the end we were really glad to have the help of experts who had visited all the resorts we were considering so were able to tailor their advice, give us insider info that we wouldn't necessarily have picked up on from websites and negotiate an accommodation upgrade.
Happy planning!