I imagine there are several worries you've got over this problem:-
(1) water spilling onto the floor, being a trip / electrics safety risk and possibly damaging the house and furnishings; and
(2) if you're on a water meter, the high costs of wasting water
Re (1), is your wife at the stage where she can learn new things?
What would happen if you could buy taps your wife couldn't work? Would she give up and do something else less inconvenient ... or become frustrated, destructive and try different and more damaging ways of amusing herself?
Could she be distracted from using most of the household taps by a water toy (eg a mini fountain such as you get in a garden centre)?
Can you get advice from a professionally qualified Community Occupational Therapist on types of taps or other strategies which might help you solve the problem?
Re (2), I was able to get my parents' water bills reduced by switching them from water-metering to a standard charge based on the number of people living in the house. I was only able to do this with the sympathetic help from someone very senior in their water company. There are a range of other schemes to help people who can't afford high water bills because of low income.
Good luck. I hope you can find some way of sorting out this very difficult problem.