oh it sounds like it's going to be fun!

One thing to keep in mind is that if Nan comes it might change what type of accommodation you can book. Ie standard rooms might not necessarily accommodate for that many people.

We really enjoyed Las Vegas with our 2 small kids (4 and 1). that said, it really was seedy lol. BUT, we mostly hung out around the strip and ate lots of icecream and mostly, in all honesty enjoyed the SUPER CHEAP accommodation. like, we were paying only US$30 a night for a 4 star fully equipped apartment that was poolside AND it included dinners! you can't beat that value man lol!

I wouldnt drop hawaii either. everyone that i have spoken to that has gone there has just fallen in love with the place. it is also quite affordable (well, as someone booking from the US...what with the US economy what it was in 2012 they were struggling to get people to spend money to go there!).

could it form part of your stopover?