Yarn junkie
A person who plays with yarn to the point of questionably high level superseding all other activities. Usually a Knitter, Crocheter, Spinner, Dyer, Weaver or other Wool enthusiast. Yes, they are addicted. No, there is no 12-step program due to lack of interest in quitting.
She knit 12 pairs of socks this month AND bought more yarn because she is a total yarn junkie! Can't help herself!