Hi there, I work for Turquoise Holidays based on the Northcote Road and would love to share some suggestions.
The Westin is brilliant, very close to One & Only but a much better value for money option. If money isn't so much of a worry then One & Only is brilliant or the Madinat Jumeirah is also wonderful.
For your family I would definitely recommend staying on Jumeirah Beach - that is where everything goes on. You can go to another hotel for lunch etc. with ease.
I hope this helps! Grace x