Spent a few minutes looking at the site. Looks to me like it was hit by Google's Penguin 2.0 update [1] that targeted sites that had low quality links pointing in to their domain (in particular inner pages).

Probably not the sisters fault, but the site has done a lot of reciprocal linking in the past which Google really frowns upon nowadays. There's prominent page on her site featuring some of those links: http://www.portraitquilts.com/info/links

She also has some links from pages that are selling or exchange links to spam/escort sites:

http://www.iwr.com/gifts/crafts.html http://www.livebusinessradio.com/trade/recip.cgi

Again, probably not her fault. Google is doing their job but with so much misinformation about SEO and link building out there it is easy for people to accidentally get themselves in trouble.

If anybody is curious, I used ahrefs to pull in the backlinks to the site: https://ahrefs.com/site-explorer/refdomains/subdomains/www.p...

There are some other examples of link spam in there. Penguin would be my guess after a quick check.

[1]http://searchenginewatch.com/article/2279845/Googles-Penguin...