She could also try creams/ ointments containing tretinoin, hydroquinone, arbutin, azelaic acid, niacinamid etc. It is advisable to use these at night. If these do not seem to help, you may consider seeing a dermatologist for alternative management.
Hope this is helpful.
I've been trying salderma copper peptide cream for scar reduction and, although it's probably not actually possible :p ..I swear I can already see results. Your friend might want to do some research on copper peptides and maybe give them a try!!