Not so. There, you unambiguously have a list. If you have a list with a comma in an item, you separate list items with semicolons. So if Ayn Rand was the mother, then it would be "To my mother, Ayn Rand; Jimmy; Bobbie and Sue." The original is difficult because, if "Ayn Rand" is actually subordinated and not a list item, then you don't have a place to put a list separator at all.
Well, an argument in favour of the Oxford comma in that sentence is that Ayn Rand didn't have any children, as anyone who would care for the name would know, so it's clearly a list of three items. :)
