Hair dye gone wrong please help?

My mum had bleached hair with a light blonde dye. She came to redo the roots again yesterday with the same colour that was already on her hair. This colour is a professional hair colour from a hairdressing supply shop. When she applied the colour her hair went blue/grayish. We have now tried to fix this by putting a golden blonde colour over (I have heard that the warmer tones cancels out the blue tones) Now her hair is a peachy dusty blonde colour. We need to get it back to just an average light blonde but without using ash colours incase the hair reacts to the blue again. I know that the majority will say to seek a professional hairdresser however she is going away on Tuesday and the hairdressers are all closed and to be honest are too expensive. Just looking for a quick fix really. I was contemplating putting the bleach powder on to get it lighter. Please no nasty answers or anyone saying we should have done it professionally ect everyone does it please can you suggest any fixes that we can do at home today? Thanks