She might have been better having highlights that were only a couple of levels lighter rather than say 4-6 levels lighter depending on her natural colour and what level they’ve lifted it to. If she’s really not happy she should go back to the salon and ask them to tone down the highlights so that the contrast is less obvious. However, when you have a major change with your cut or colour, it can sometimes take a few days to get used to your new look and it might be that she just needs to live with it for a week.
Also, if she does go back, the salon may charge her for toning down the colour as it’s not their fault that the client changed her mind afterwards. Generally, salons and hairdressers want their clients to be happy with their new look so they might only charge her a nominal amount, but it depends on the policy of the salon.
