I have this idea for a story that involves medieval stuff, so I spend time trawling through wikipedia's lists of medieval people, cherry-picking names. I come across
Melisande every now and then, and I really like it. It's a perfect princess name. I think it's very usable in real life, certainly just as much as
Millicent.
NNs could be
Mel, Meli, Melis,
Sandy,
Sandra?