My granddaughter wants to dye her hair(previously colored about a month and1/2 ago)from dark brown to a light brown/blond. We cannot afford to do it in salon. What can I do to help her myself.

Well I recently dyed my hair dark brown and wanted to go lighter so since my hair is so dark I went for almost a blonder color.Just look on the side of the box and pick which color your going for.It worked for me so maybe it'll work for you too it's worth a try.

my granddaughter wants to dye her hair(previously colored about a month and1/2 ago)from dark brown to a light brown/blond. we cannot afford to do it in salon. what can i do to help her myself.
She can use sun in - with will leave it a shade lighter, don't use too much though... otherwise your hair will be lighter still

Please do not use sun-in on your granddaughter's hair. In order to go from dark to light brown or blonde without the red/orange tones, it will require bleaching and toning. If you can't afford to go to the salon, try using L'Oreal Superior Preference Les True Brunettes. It will lighten dark hair a few shades without the brassiness.