You are probably talking about the Chitosan, right? I, myself, am also VERY (deathly) allergic to shellfish. I have had wine that was cleared with Chitosan (as well as other things - it's in alot of stuff, like binders for pills and things) and have not had a reaction. The Chitosan is actually made from the shells of the shellfish not the "meat" itself. And the meat is the part of the animal that contains the actual allergen.
I would say she'd be fine, but of course I am no doctor, hold no liability, etc, etc. Just my two cents.