I have no experience with Bowflex largely because they look like an expensive way of separating someone from their cash. I have a friend with one who never uses it. Just sits in the basement.
I bought my first set of free weights in 1972 when I was 13. Cost $16 then. I still have it and have added a couple of more weight sets to it(one was given to me). Have a bench that is fairly portable that I got almost 20 years ago for $39.
Barbell, dumbells are adequate but adding a curling bar and a triceps bar can also help give you a better workout if you are inclined. Nice to have enough stuff where you are not always changing weights. I can go as high as 150# on the barbell I have as that is all I would trust on it. I have to do a lot of reps but BFD(28 on my first set of benchpress). 2 dumbells with 40# each and I can get a decent workout. With your wife you would need some smaller weights.
I do bench, upright rowing, military press, tricep curls, bicep curls, situps and flys. It is a decent enough workout for overall strength and toning.
I do wish I had a Lat machine as I have nowhere to do pullups. That would get some serious use if I had it.
If I lived in town, or near, I would get a Y membership so I could lift and swim. Swimming is great excercise if you can swim good enough to actually get a workout from it. Most people can't and don't. I see some of them swim for excercise and they are just wasting their time if you ask me. I live on a lake so in the summer I can swim plenty but I would sure like a pool. I am almost an hour away from the nearest Y though.
I also live in a forested area and hike alot. Bike some.
Just FWIW, with some variations in technique between sets you can do pushups, pullups and situps, working every upper muscle group. Might get boring though. And that is something I tell people anyhow, do different things to keep it interesting. Lift, jog, hike, bike, swim, etc. More fun and better rounded excercise plan anyhow. If you get bored with it you will probably quit.
Excercise is the one thing I have pushed harder on my patients then anything, incl smoking cessation. I know if I can get them to excercise they will cut back on the smoking and it will amke it easier to get them to quit.
Long winded response. Good luck.