I suggest to get your mom a 17 or 19 inch monitor if she has that much trouble seeing a computer screen.
Also you can increase the font size separately in a browser.
When I bought my 22" she asked for my 19" widescreen LG so that she could give her 19" 4:3 to a friend to replace his 17" 4:3. We switched and I ended up with the 17" (Metro VGA only) she is thinking of going to the 17" and giving me back the LG.
I wish I could afford to get her a 22' but my spending money has recently shrunk to practically nothing. Maybe I can save enough by her next birthday. I'd trade her mine but there is no way I could go back to a 19" now that I've been witness to the glory of a 22" with 4850's Crossfired.
I might try to locate some older drivers and see if that is the culprit because the exact same hardware was fine before the re-format.