Pity that February is still rainy season in Bali, as that would have been ideal.

Phuket, Thailand would fit the bill - Trisara - which has just done a huge renovation - would be my choice.

Langkawi, Malaysia - Four Seasons Langkawi - great for kids.

The about-to-open Oberoi Al Zorah, just 30 mins drive from Dubai airport and perfect for families - http://www.oberoihotels.com/hotels-in-al-zorah-ajman/

One&Only The Palm Dubai - also great for families.

How about Mauritius? There are non-stop flights there from the UK. Best here for kids would be Four Seasons Anahita, although I prefer Constace Le Prince Maurice, which also caters well for kids. Mauritius always has great kid's clubs.