you could try to have a clear glaze put on her hair - a good one is redken's EQ colorshine i think it is called. it just puts a clear shine glaze on your hair. this might help it look healty and not dull.

I have just had some highlights done and I hate the colour. It looks really washed out, no shine...a very dull caramel blonde...not happy. My natural colour is medium brown...what can I do to add some definition and shine back into a new dull washed out colour? Plus will it be extremely damaging to my hair, to have another colour applied so soon?