If your mother was willing to work a couple hours a day, I would suggest dropshipping products over affiliate programs. Your profit per sale is usually higher at around 25% and you don't have to maintain inventory or ship packages. Many eCommerce packages are available with some of the best being open source.

This wouldn't be work like making products but answering a few emails, finding backlinks, adding products to the site. It doesn't even have to be her alone but could be a family endeavor to kick it off the ground. My retail business is going to gross me $25,000 (US) for 2004 and I probably will net $15,000 (US) and I only spend 4 hours a week on it currently. I also maintain my own inventory, package goods, ship them and evaluate new products. Next year, I plan on opening 4 new online stores with different products. Three of those will be dropshipped products and the last an AWS store. I don't plan on putting in much more than 4-8 hours a week on any of them but will increase my time on my main retail store to 20 hours a week with active promotion instead of passive promotion in order to increase yearly sales to around $100,000.

If you can only do one site, I would suggest a combination site. There is a lot of information in the form of public domain books that you can base a site off of. This would allow the content to draw people and then you can promote a variety of income through affiliate and dropshipping to your visitors.