She tends to use worsted weight yarn or fingering weight depending on what the customer chooses and for plain hose knits them really fast using some sort of technique where you knit both at once on the same set of needles. (I'm still a definite novice knitter, so I don't know the best details.)
She's actually been going for a while now and had to close off her waiting list when it got to a year long wait for the bonnets and hose she offers.
The plain hose are still reasonable prices, but she charges a good bit more for argyle and balmoral hose as well as cable knits and popcorn tops.

Thanks for the comment about her undervaluing her time and talents. I tend to think she does, but she really just enjoys knitting and wants to offer something a bit more accessible.