I'm glad to see that your mom chooses function over form when the occasion calls for it. I like that kind of person, LOL! There are plenty of things one can do to compensate for the inevitable messy look of a garden--for example, some strategically planted flowers, a little fencing in the right place, etc.
I'm into prairie plantings and so I have read quite a bit about people who like to grow native (ie, messy looking) plants in places where their neighbors hate that "wild" look. One of the tips that made sense to me was that if you pay very close attention to EDGES you can fool the eye. For example, a prairie planting that goes all the way up to the edge of the road will look terrible to most people accustomed to a trimmed look. But if you instead closely cut the grass along the verge of the road and install a cute fence between that and the taller native plantings, it looks like a picture out of a magazine. It defines the area for the eye. The other nice tip from the prairie folks is to involve your neighbors whenever possible in what you are doing. In your mom's case, sharing her cukes will go a long way toward feeling comfortable with the neighbors!
But, I think you weren't really asking for design advice, LOL! I think your question is really about the squash fungus? We talked about fungus on tomatoes on this thread:
I think this might help you. I don't think the fungus is 'caused' by water so much as encouraged by it. At this late stage in the season, it might be established well enough that it will be hard to get rid of. A biofungicide MIGHT help them outgrow it, if you want to try that. Can you get ahold of some dripper hose or seep hose whatever it's called? That way you can give them plenty of water (which they need) without wetting the leaves.
I have some squash plants that look like they are dying off right now--at this point, I just let them go. Earlier in the season I am more energetic about treating them if they need it to get off to a good start, but at this point I'm too busy with other things... For me this time of year is about taking notes or re-thinking for next year, while I feverishly deal with the harvest I do get. Maybe others here will have a more proactive attitude, LOL!