I am sometimes asked to help my daughter cook for large groups of her inlaws, and several of them are gluten intolerant. I need to know if there is a list of pre-packaged foods such as spaghetti sauce or steak sauces for instance, that are gluten free.

This is a global website. What might be available in my location might not be available in yours.

Thus, your location is important.

Gluten-free is the hot topic that has replaced autism. Here's one grocer site that has made a list of gluten-free products --

Gluten Free Product List

Here's another site that had pages of gluten-free products --

Gluten-free products

In most grocery stores they have entire sections dedicated to gluten free foods and drink. It's great now that they are expanding with more variety, now there is several different brands of cardboard to choose from ;) :D I kid, I kid. These girlfriend food available now is very tasty, and healthy :)

Maybe this will help

Gluten Free Indy - GF Food Lists