My mother is listed as living, but she has been deceased for years. Please help me know how to change this status.
Thank you for contacting FamilySearch. Go to your mother's person page. In the Vitals, scroll down to Death, click Edit. Click Deceased, add the death information, and the reason why you know this. Then Save. This should correct your mother's record.
We attached some additional steps for your to follow,
How to I change the status from living to deceased?
Find the person in your private space in Family Tree, and enter death information so that other Family Tree users can view the record.
If you have difficulty with this process please reply to this comment.
Thank you for using FamilySearch/Family Tree and we wish you much success.
Remember to add sources for your mother to verify her death. For example, Findagrave, death certificate, Funeral programs, obituaries, Social Security Death Index etc. Once you have marked her deceased as @AmericanLady1953 and @lstolk36 indicated above you may find some research hints that you can add as sources for your mother.
Hopefully this may help.