I've read bits of Yarn Harlot out to my housemate - she doesn't knit but she is Canadian.

What you're saying mirrors a lot of the reviews I've seen of that - I thought it sounded interesting so I looked it up, and... yeah, a lot of people loved the first half then wanted to shake sense into her by the second. Someone said it sounded like the writer had got bored of things by the end, and it reflected in the book.