With a broken wrist you normally can expect return of some use of the hand within a month or two, although the healing time can vary a lot depending on the location of the break and "vaguaries of age" that can affect the rate of healing. It likely will be quite a bit longer before she can exert significant effort to holding or lifting things.

For normal case with both hands working I've tried lots of "jar openers" that promise but don't deliver, and now keep a couple of simple "strap wrenches" in the drawer for tight lids. It's difficult to find a good one, and the more common cheap ones use a plastic strap so stiff that it requires both hands to adjust to fit - one wrench on the lid and the other on the jug. Of course that's not much help with your present problem.

I've tried a number of "devices" for holding a jar so that you can remove a lid one-handed, especially for about the past 8 or 9 years since Lin's stroke weakened her use of one hand. NONE OF THEM WORKED.

About the best I've found is the homemade "whittler's bench" where you can sit down on the seat and step on a pedal board to close a pair of wooden jaws onto "just about anything." The problem is that I have to go out to the back yard behind the shed to use it (since she gets lost when she goes outside), and it's getting pretty weather-beaten. Since I do have two more or less usable hands I usually just use the straps.

I'll be watching the thread to see if someone comes up with a "bottle vise" that will fit in the kitchen.

John