I agree w/ what Jo-Ann has said. You stated that she was a recent widow. Was her husband sick for sometime? If so, perhaps she is tired as well as afraid of drs. Although this is no excuse for her ignoring her medical condition, it might be a reason. Does she have children? Grandchildren? If so, you might use them as the reason she needs to seek medical advice ASAP! Ask her if she wants her kids to lose both parents w/in a year. The bottom line is that unless she is willing to seek medical help, there is nothing more you can do.
Lots of prayers for you!