Jack?
"My wife is convinced that in order to minimize healing and to sail "safely" we should only sail with the headsail (135% genoa). "
Meaning no offense, but your wife obviously knows nothing about boats or sailing and just as obviously is terrified of sailing. There's nothing wrong with that, we all started by knowing nothing and she's just concerned about the safety of her family.
So I would suggest that the first thing you need to do, is to send HER (or both of you<G>) off to something like Womenship, a women-only sailing school in Annapolis, or a similar "ladies it is just us" class.
The Sabre28 is a good boat. Matter of fact, Sabre might recommend something closer to you, they're outstanding folks. But your wife is operating out of FEAR not FACT and that's something that needs to be corrected immediately. Both for safety and for harmony.
Many boats in that size range will be able to carry a 150 and mainsail, both full, up to around 14-15 knots without reefing. If you trim wrong, sure, you may be heeling way more than you should. But then again, on a small boat it is NORMAL to walk on the walls, so to speak, and if that's what is bugging your wife, she needs a chance to come to grips with it. (She may simply not have faith in your sailing skills or experience, or she may simply have seen Poseidon Adventure once too often<G>)
If you ring up the folks at Sabre I *know* they will be glad to speak with you. They can tell you exactly how soon you should be reefing, and how much sail to carry in what winds. Typically around 15 knots you can be reefing down one reef line in the main and rolling the furler up to 130 and you'll flatten out the boat without losing any speed. And by 20 knots you'll need to have one reef line, maybe two, in the main and roll the genny down to 100%. But the exact speeds will vary with the boat, and I don't know yours. The folks at Sabre certainly do. If there's any way you can take your wife there for a VISIT...that might be the best way to get started of all.
Mesh lifelines are a "must have" if the kids will be on deck, as are comfortable PFDs for everyone. I've made a habit of keeping mine ashore, so it comes out of the car with me and I set the example that it gets put on BEFORE getting in the launch, and stays on until we're back. Kids complain less when they are just imitating what the big folks do, and the comfort level (mental and physical) is a big thing to work on. For the wife and kids to be comfortable about going in the water, for their PFDs to be comfortable too.
The big thing is, don't let it snowball into a fight, go for the confidence and the facts and the rest will smooth out. (And if she's really just terrified of the water...welll...sometimes that happens too.)