The tips are added automatically, for all 4, on your ship board account. Count on about $11 per person per day. Although the tip is not "compulsory", unless you received terrible service, you really shouldn't ask for a reduction of the tip amount. The crew rely on it as part of their income and it would not be fair for them.

On a typically formal night, men wearing suits and ladies wearing a dress is acceptable. You may see pictures with men in Tux and ladies in fancy gowns, but that's not typically the case.

If you are in an inside cabin on deck 6, the "family room" means that you can sleep 4 in the cabin. More than likely, it is a typical inside cabin with 2 fold-out upper-berth. They will unfold it for you in the evening, and fold it back in during the day.

I had the opportunity to be in a cabin with 2 upper berths when our kids were smaller and travelled with us many year ago. It was an outside cabin, and I have 2 boys. It was crowded.

A typical cabin is less than 200 sq ft, and that included space for the washroom, closet etc. With 2 daughters at age 16 and 12, the washrooms will be an issue. It is wise for Dad to plan ahead and scout out the nearest publc washroom location to do his business if needed.

We hardly spent anytime in the cabin except sleeping and changing. There are so much public areas and so much to do that you will only feel crowded just before going to bed or first thing in the morning.

Here is a tip. Mom and Dad get up earlier, dress and ready before waking the kids. While the kids are getting ready, Mom and Dad go out for a morning stroll on the promanade deck (deck 7) it is about a 30 minutes walk around the whole deck and you will find a lot of people doing their morning jog or walk there. After your walk, go back to the cabin and collect the kids and get ready for breakfast and a full day of activity. You probably won't see your cabin until it is time to change for dinner.

At night time, do the reverse. Send the kids to bed around 10, then you two can go for a stroll or dancing at the night club.

All food and beverages are free except soft drinks and alcoholic beverages. If your kids drinks a lot of soft drinks, buy soda cards.

Beer, wine and cocktail prices are typically about $7 to $10, very similar to a typical fancier hotel cocktail lounge pricing. Wine by the bottle would be from $35 and up. You can ask them to re-cork the bottle for you and save it for a later day. If you are not heavy drink, a bottle may last 2 to 3 meals.

Bringing alchol on board is not allowed unless it is wine. They will charge you $10 a bottle for corkage fee so you might as well buy it form them. I have seen people smuggle booze on board and they even traded methods on how to sneak them on board, but I am not an advocate of that so I won't comment.

Here is 2 links that you will find useful.

This is the Fodor review of the Queen Mary
http://www.fodors.com/cruises/cunard-line-695745/ships/queen-mary-2-695774/

This is the crusie critic "at your service" page. It has links to articles on cruising, from packing to what to expect for a first time cruiser.
http://www.cruisecritic.com/features/area.cfm?ID=13

Good luck on your first cruise, you'll enjoyed it.