I don’t know if such a thing exists, but I have to look after my property and have a reliable plumber, a reliable electrician, a reliable gardener and a reliable odd job man who manages the rest. Most were picked on the recommendation of friends or local advertising. I think the only extra problems might be with the roof. (I do have a roofer, but have only needed to use him once in the last 10 years).
If these could be set up for her by a relative maybe, then she would be OK and less anxious.
Of course this doesn’t cover the ‘be responsible if things go wrong’ bit, but I have not had a problem with any of the work done for me.