I've sailed since i was small, and introduces my husband to it who loves it. I belong to a Yacht club in north Wales in the UK and I am always surprised how many wives/girlfriends don’t sail because their other half has frightened them half to death. Be sneaky and take her out for sails on beautiful days and don’t talk about when it all went horrible wrong and had an awful sail. Keep everything low key and make sure her opinion is matters, There is nothing worse than in my case wanting to go to Scotland and having to go to Southern Ireland again because that’s is where he wants to go.
Get her involved with the deck work. Show her how to start and stop the engine and how to steer the boat. Don’t do everything yourself, take the time to show her. Also, many woman, find that they just end up doing the chores they do at home in worse conditions, while the kids have fun in some cases, couples who have sailed for years find that the wife's skills are hardly up to scratch as the kids have done all the crewing work on the boat and wifey is in the galley again.
And it’s hardly a holiday if you spend Breakfast noon and dinner in the galley cooking for 4 on little more that camping stove. Have bbq ashore, meals out. Trips off the boat. Allow her time to herself there is pressure privacy on a boat. Even without kids. There is a difference between sailing and cruising.
Read any of the book by Lyn Pardey, they are all good and give opinion from a woman’s point of view.
Above all else have fun doing it and good luck and it’s raining in the west midland in the uk.