You can either search in the upper right box (with limited success) or use google.
In the google search box type:
site:www.ricksteves.com {your search}
Don't put in the curly brackets of course...
In regards to traveling with Celiac, my wife lived as one for years (only later to find out she didn't really have it). It was practically impossible for her to eat anything in Japan when we were there. As well, I could see you having quite A LOT of trouble in Austria, Italy and Slovenia just trying to tell them what you troubles are. Ireland they will at least know English, but you will probably have trouble finding food that is safe.
Lots of European groceries have Celiac food available (we did look into it, just for curiosities sake). As well, make sure to bring a bunch of snack bars, etc. as you will probably find that many restaurants won't be able to help. As she probably eats a lot of salads here, I would have your mother look into those mainly because you can generally see what is in the food (most of the time) except for the dressing.
We have had very limited luck in bringing one of the 'Celiac Cards' with various languages on it. Pretty much any time you show something like that to a server they either don't understand it, or say nothing is safe, so don't rely on it. As well, one of the biggest issues servers have in regards to gluten issues is lack of knowledge about it. They just don't understand what it means. Also, it is common for servers to see customers with dietary requirements as just being 'picky' which leads problems.
I think it boils down to "take all the pain you have here going out to eat as a Celiac and then throw in a language barrier".
Traveling with Celiac is hard, but we have done it, so it is possible. :-)