Thanks, Dicey. Yes, she SHOULD be getting the larger of the two, but, of course, the SSA has different ideas. Mom is visiting my brother now, but has some correspondence from the SSA at home, so hopefully that will be sorted out.
And you're right about the book. I'll look online.
Just a caution to others, and I know it's been said on other threads. We started sorting out their finances a few years ago. Thought we had a handle on it. WRONG! Many accounts were in only my father's name, or my mother was a user, but not owner, of accounts. I couldn't convince them to make a trust, as the attorney they consulted said they "didn't have enough assets" BS! Talk to your parents, and try to get it sorted out BEFORE you really need to, including minor issues like credit cards, savings accounts, etc. My mother is far from helpless, and worked as an office manager, so she knows how to do much of this stuff. It was just easier for her to let my father do it. I'm not complaining, though. At least she can afford to live on her own, and stay close to her friends and family.