Craving for unusual things. Problem?

My cousin who is a 35yrs old working woman wd a good career n family. Sometimes she is stressed due to personal n professional matter.But till now she leads a healthy n Happy life. Recently she started to fall for smoky flavour Firstly, she cooks everything wd smoky flavour.Then suddenly she started to brush her teeth wd charcoal (during her childhood, her granny did it).Then now she s addicted to charcoal .In the morning, in the night she brushes her teeth wd charcoal only to feel it's flavour and only to bite the charcoal.From last one week, she keeps charcoal in her bag and starts biting it whenever she can.She s very worried for ds wierd behavior and tries to ignore.But she can't.She only tells me about this.I m too worried .Whom to consult? Is it something related to mental problem ? Plz help her