What happens if an 80 year old ignores squamous cell on her face?

My MIL has had several squamous cell moles removed from her face. The last one was really deep, left scars that forced her to change her hair style and took much longer to heal than she anticipated.
She has a new one on the corner of her eye and she has decided not to do anything about it. She says that she’s 80 years old and either this or something else will probably kill her in the next 5 years anyway.
She is pretty much wheel chair bound, although she can transfer to the toilet by herself. She has rheumatoid arthritis as well.
The little bit of research I’ve done leads me to believe that she will likely be more disfigured by ignoring it than by having it removed.
Has anyone had experience with this? Any idea what the prognosis is if she ignores it?