As for my friend, she is very appreciative of the "salary" and she would never be offended if I asked her to stay in the room. But I would feel guilty about it. It interesting to me that people are saying that the workers on the ship deserve a tip for their work but do they not also receive a cruise as salary? IF my friend did nothing but WORK for the entire cruise, it really wouldn't be much of a salary... just as the crew members work rather than enjoy the cruise. If the crew members deserve a tip... than certainly I owe it to my friend to make sure she at least gets as much out of the cruise as possible. Just trying to be fair.
I think this keeps coming up for a lot of us as a sticking point because it's confusing.
1) You bought the person a cruise.
2) ...with the expectation that she will do...what specifically?
In some posts you indicate that she is there to babysit, but in other posts you indicate that you will be
feeling guilty to have her babysit. Was this really a transaction for child services, or were you just bringing the friend along to be nice? If the latter, I don't think anyone is going to judge you for that, but if you were clear about it, it would make people stop questioning the specifics of the arrangement.
For example, you say: "IF my friend did nothing but WORK for the entire cruise, it really wouldn't be much of a salary... ", but as far as I know the only thing you've mentioned is her watching the kids for a few hours each night, and you also seem to feel guilty about that part. So how does 'working for the entire cruise' become part of the conversation?
If you've employed her to watch your kids for X number of hours per night, and the payment is a cruise, there's no need to feel guilty and you should make whatever arrangements make YOU and your kids the most happy. (While tipping the servers.)
If she's a friend and you offered to pay for her cruise just to be nice, with a tacit understand that she'd maybe watch the kids sometimes (but you don't really WANT to ask her to do it), then saying you brought a babysitter along on the trip is what's caused a lot of the confusion in this thread.