I'll name these twins as my parents would have.
My male twin would be Roderick Kenneth, as that's the name of the child born after me;he lived only a week.
My female twin would be Yvonne Freda.Yvonne is the name my parents considered for me, after my mother's childhood friend. And Freda is my mother's name.
Freda Yvonne has a better flow,but then there would be 2 Fredas in the household, too confusing.