Do her internet troubles seem to correspond with rain? I suddenly recalled an incident from many years and several states ago. I had great internet, but when it rained it went to shit. You call the cable company and they come out the next day and everything is fine. I went through several iterations of this before I got a tech that decided to go maximum effort and look at the cable between the pole and the house foot by foot.
A god damned squirrel had chewed through the insulation.
Something to consider, assuming her place is wired similarly.