"Older sister" and "younger sister" names?

Interesting question and something I've never really considered before, but No, I would not consider birth order a factor in naming a child, in the way you mention. The only issues with multiple children of either gender, to me is avoiding rhyming names or too similar sounding names, even if I liked both names. Like Cynthia and Melinda which I both like could become Cindy and Mindy which I don't like.