Put me down as another who thinks you may be biting off more than your wife can chew by trying to bag Hamlin along with Katahdin. I've climbed Katahdin twice and Hamlin once, and I'm pretty sure that would be a long, difficult hike to attempt both in one day. And you'd pretty much be stuck once you tried for the second peak.
On the other hand, I have never headed from Baxter Peak toward Hamlin , or vice versa, so I don't know how hard that may be. It seemed pretty flat on the top of Hamlin, but I don't know how long that lasts.
I've never been on the Saddle Trail, either, but is it really easier to hike all the way in to it, along the Chimney Pond Trail, I presume, and then have to climb it rather than just climb the Abol Trail? Abol is slow going, but I don't remember it being particularly tiring. Both times up to Baxter I went via the Abol. Chickened out the time I was on Pamola (the trail was actually closed, but I made it that far anyway) and found the Hunt Trail too difficult when I tried that by myself. Yeah, gave up too easily, but that's the way it went.
I was pretty scared at one memorable place when I descended the Hunt Trail in the rain following my first successful Kathdin ascension. I had to ease around a boulder, and there was just a straight shot down a chimney behind me with nothing but clouds visible down it. I don't think we'd gotten off the trail, because I'd joined up with two people who claimed they had a couple dozen ascents between them, so they should certainly have known where they were going.
There are a few places on the Hunt Trail where you need to use metal handles to haul yourself up or let yourself down the rocks. Hard to do while carrying a walking stick.
North Brother by itself is a long enough hike without adding Fort, never mind South Brother and Coe too.
Not to sound too gloomy, but I recently picked up some old Appalachias at our library's book giveaway and one of them had Gene Daniell's accident report on the man who died trying to climb (or descend) Fort Mountain (if memory serves he was posthumously awarded the ascent because it was his hundredth of the New England Hundred Highest), and one of the factors Gene believes contributed to the man's death (I'm sorry I can't remember his name at the moment, but he was a professor at Tufts University and the event was fairly newsworthy at the time) is the difficulty of reaching Baxter State Park and the inclination of peakbaggers to throw caution to the wind because they don't want to have to go all the way back to the park if they don't bag the peak now. Well, Susan and I blew off Fort a few years ago because it seemed too risky to try for it (light sleet, clouds constantly scudding through the col), and we'll just have to go back. Don't underestimate the difficulty. We don't want to be reading about you in the paper, or wondering if this dead person was good ol' Double Bow.