The reason modern pads and tampons were invented, was because the homemade cloth ones, did not work and were a terrible hassle. A speck of blood is not like urine. Does she want to spend her days washing and soaking out bloody pads?
Here is a blurb about this. http://voices.yahoo.com/heavy-menstrual-period-leakage-pr...
HAS SHE SPOKEN WITH HER DOCTOR? Hysterectomy should be an option. Or is this blood not actually coming from her uterus?
And yes, I have had heavy periods with bleeding as described. I needed the pads because they have the plastic liners. I have even been known to use 2 of the overnight liners at the same time as well as the very largest Tampons and still have to change the tampon every hour or 2 hours on some nights. I cannot image that any homemade fabric options could work any better. If anything, it would be a horrible mess. They make XXL overnight pads.
There is no reason for her to not be able to function.
Otherwise if she can use the largest tampon by Tampax, and yes, she will still have to change them very often. "Ultra Tampax, Tampons."
Adult diapers will not work, because Urine is not the same as a menstrual cycle and will not absorb the same as feminine pads,