If it is appendicitis, she'll need surgery.
If she needs that kind of invasive surgery, there's a very good chance she won't survive the week. She's almost 80 years old, with virtually uncontrolled diabetes, and is so frail she can barely even stand up anymore.
Her last surgery, cystoscopic surgery to remove a (non-malignant) bladder tumor, really wiped her out. And that was non-invasive and with light sedation. Actually cutting her open under full general anesthesia? She'd better get in some harp practice.