That would be "widow" or "abandoned wife" not "single mother".
It's not splitting hairs it's just proper logic.
People don't use that much logic anymore. Since the year I was born, my mother was a widow, and people were always referring to her as a single mother.
Well, that will be such a comfort to my friend Judy, whose doctor husband passed on suddenly at age 50 leaving her with an 8 year old daughter.
SHE refers to herself as a "single mom" because there is no longer a father for the child. Then again, you know better, right?
Did any of your siblings develop intelligence once they got past the diaper stage?