Sainsbury and Morrison's both do a good range of gluten free products, including biscuits, crackers, pasta and soups. But why not make your own?
Cook the veggies you want, and whizz up half in a blender add to the other half to make a thick soup, or completely blend to make a thinner one. Use salt, garlic and herbs and spices to make it tasty, or go here for some more gluten free recipes:
Many thanks skyep, merciasounds, pastafreak and gravitate. Got just what I wanted at Tesco's today, expensive, but gluten free foods always are. If this visitor comes for a meal again I will probably make some soup for her myself from the recipe provided by merciasounds.