I am making my mom-in-law a platter with their family tree on it. I love The Work*Shop (www.theworkshopaustin.com) on W. 6th Street, where you paint pottery, as well as many other artsy & crafty things. I did this for my granparents last year for Christmas and it was very well received. It's very personal for them, from you, and is a special one of a kind gift. Another thing to do along those lines, if everyone is in the area, is to make a set of plates or wine glasses, one made by each son, daughter, in-law, and then hand prints of the little ones.
I know that's not exactly the line of thinking you were on, but something I think is super-cool and unique. Another thought is just to think of something she really loves or appreciates, but does not do for herself. Maybe she's always wanted a high-dollar purse, coat or to go to a particular musical, play, concert. Tickets would be awesome. Even though she would probably take her husband or a friend, it would be HER favorite music, or whatever.
Good luck! She's a lucky lady to have such a thoughtful daughter-in-law!