I'm assuming you know she has "skin cancers all over" because a doctor diagnosed them and the same doctor needs to be aware of her smoking and tanning habits - it should have been obvious to the doctor - so I'll also assume if she saw a doctor she was told that both habits are putting her in a very dangerous situation and she is choosing to forgo the wisdom of stopping both - maybe you can help her.

Melanomas are the ones we most worry about in terms of risk of metastasis or spread to organs inside the body and in terms of a high death rate if not treated early.  Again,she would know if that was the diagnosis.  Today's news tell us though, that even non-melanoma skin cancers are worrisome because they can mean a risk for other cancers elsewhere in the body.  Non-melanoma skin cancers can also grow deep in to tissue and disfigure the body - especially the face.