I need a hairdressers opinion!!!!pls?

Im doing a ladies hair on saturday (14 Feb).She is very blond and her hair is really really dry.So now she would like to go dark ago (level 5) and still keep a fair bit of blond highlights.Now i know i cant go over with bleach and put highlights in her hair cause she is blond and broke hair .already so whats i'll do is put foils in and in stead of bleach i will put a treatment in and for the all over colour i have to apply a red first and rinse and reapply the brown.How can i do this with out letting the foils fall out and rinse every colour.Please let me know what u would have done or do.This might take the whole day but with your help of a better plan i can go a bit faster.pls any tips will be awsome.thanks .i know it doesnt make any sense i only have like 5 mins to ask.but how would u fill blond dead looking hair and keep some highlighs.thanxI need a hairdressers opinion!!!!pls?
your story is a little con fussing but it sounds like shes really blond n you want to put some brown bak in there Just do low light with the brown do it with a demi permanent it wont damage her hair more than it already is. then you can Just tone her with like a level 12 so it can lift the rest of her roots a little i do it all the time.