Anyone looking to sell you (your daughter?) something HAS to base it off of some sort of water testing (they'll typically test on-site [bacteria testing needs incubation time, I believe, so that would likely be off-site and not something that most "one size fits all" salesmen would address]). They should show you what those tests showed: of course, take their numbers/tests with a grain of salt (partial PUN there).
I'd start by finding out what the municipal water folks are treating for and for the quality of the treated water (breakdown into individual elements tested). All such entities are mandated by law to include regular water quality reports: these are supposed to be available to anyone who requests them.
Couple that with what tests your County requires for water permits.
The following link is to a form used by a local water testing lab (which I've used many times):
https://www.edgeanalytical.com/wp-content/uploads/WSI.pdf
Clogging is usually going to occur from bacteria or mineral buildup (or a combo of). Bacteria test is pretty cheap (and turnaround is fast because of health concerns) and would be good to do. pH would give an idea on whether line corrosion could be happening: most such corrosion tends to occur within the end-customer's piping system. Turbidity should show if there's a sediment issue. THESE would be for what I'm gathering are possible issues with your DAUGHTER's water (if you're on a well then you'd be looking at needing more comprehensive tests, such as identified by your County for new building permitting). With test in-hand, and if it's point to the County, I'd go talk to the County folks: they may or may not be responsible; doesn't hurt to check with them first.
I understand how difficult this all can be. I bought a testing kit ($500 or so) from a water professional (out of state). Struggled with some readings right from the get-go. I recently had to retest and I had problems again (and then went back through my notes to see that it wasn't a new problem!). The test media (strips and such) that were included in the kit were for an older model of the tester (I got a new model, which is great, but having the wrong test media makes it all so not great). I believe that the guy is in fact good, but the story here is that sometimes even professionals screw up: if it's REALLY important one ought to get a better understanding and to look to validate the info/tests/products. I had a local well driller (and water specialist) successfully coach me through rehabbing my well: such people, with their help, compel me to pay it forward where I can.