I have only felt queasy on one out of about 25 cruises. For one thing, you should choose staterooms/suites near the midship and not at the highest point. Forward staterooms can feel movement in choppy water as well as aft staterooms can be bouncy. That helps right off the bat. The following advice for taking ginger candy, ginger pills, wristbands and any other pills/patches are also helpful. I have never used them as they make me feel too woozy, which is also uncomfortable. Bear in mind weather patterns for certain times of the years...but of course it is not always reliable. My husband and I are hesitant to cruise during hurricane season because we live in Florida and it's hot, humid and can get nasty. Your family might also simply be extra sensitive to movement. I have two friends who just can't take any movement, so they do not cruise. I want to say that she should try again, but I would book just the right place on a BIG ship, the right time of year. I think the ships with the inside malls and outdoor parks might really help her out. I wish you the best because cruising is so much fun! At least your wife doesn't have to cook, do dishes or laundry.
Holly