sounds like she may only have a court claim if she can 'prove' that the shank is thinner than it was before i.e. proof of weight before and after or some kind of expert opinion about standard of service. Doubt she has this prrof of weight and the matter hardly warrants expert opinion for a small claim in the county!
Can't see trading standards being that interested in this....If I were you I would check your local trading standards authority website (usually accessible through your local borough council's website). Read what consumer advice they give so you'll know what to expect from her and whether she is full of bull. good luck



