Don't you dare leave Tucson without getting a Sonoran Hot Dog at El Guero Canelo ^ Closest location to your hotel is on Oracle just north of Grant.

For a more typical family sit-down I would do El Charro Cafe in downtown Tucson. It can get crowded so try it on a Monday-Thursday if possible.

Pizzeria Bianco on Congress is a good alternative if you want to switch up from all the good Mexican food options.

My mom stays at that Westin semi frequently for conventions and I've visited several times. Good choice ^