What a lovely woman she is. I'd suggest that you take a series of pictures of all 18 of you working on these, and pictures of piles of the socks. Also more information (for her) of whomever gets it. I'd suggest that you keep her involved. And send her hand written thank you cards. I've never had anyone slap my face for sending a hand written card!!!! They talk about it for a long time.
In fact, I have a collection of hand written cards...8 or 9 of them, going back for years! Perhaps she will love your thank you cards as much.