Help with my moms hair

So for years and years whenever anyone dyes my mothers natural level 3 med neutral brown with lot's of gray. She picks up red and golden tones very easily. Last time my cousin did her hair a light brown with highlights it look like a big golden mess!! Anything any hairdresser does doesn't come out right, some have even said it may be due to all the meds she's on. Well my brother is getting married in April and we want to do her hair a light brown with dark blonde highlights maybe even add a few lowlights in. I think I'll use ash on her. My cousin and I have always used Clairol on her but I was wondering if anyone can recommend some pretty colors for her. I have a Sally's and an Ace's that i can go too. Also the other thing is she can't find a picture she likes but keeps saying she wants a Sandy Brown. I want her to be happy with the color since it's been years and years to find a color she actually likes. Thanks for any advice I can get!