Long-term overstay of limited leave to remain

Hi

Firstly, apologies in advance if I am posting this in the wrong place but I am new to the site. I am seeking answers to a current immigration issue that is of deep concern to me. I have outlined the situation below (with the level of information I have available as I have only just become aware) and hope that someone can offer some thoughts/advice on the situation.

The person concerned is a single 72 yr old grandmother. She has been in the UK since 1986. The first 21 years of her stay were on limited leave to remain status. However, this expired in 2007. (The renewal came around the time that the woman's daughter was fighting cancer and the fear of addressing the expiration snowballed from then.) In her time here she worked until retirement age and has not claimed any public funds. She has no criminal record etc.

Her daughter has also been in the country for the same period of time but with ILR status. She is now married to a UK national and has a child with him (the lady's grandson).

I would really like to know what her options and/or rights are in this situation and if there is anything anyone can do to help this incredibly desperate and worrisome situation. Thank you so much for any help you can offer!