help for my mom ASAP!

my mom had honey blond streaks in her hair. she loved it. she had to redo her base and it Took out the streaks. she colored it dark brown because medium hasn't been working as well. the problem is the dark came out to dark almost black. she hates it! can she still put the honey blond without it looking odd? it's jus the box streaks you can buy at walmart. or does she need to go to the beauty supply? if so what to use? bleach?

The same thing happened to me but instead of waiting I redyed my hair and it came out horrible! go to a professional!!