I guess the reason why I like Sévérine so much is that, at first glance, the name looks so "light" and feminine and playful - but it has sort of a hard core. Which makes it a very strong name for me.
So how about choosing a middle name that is just the opposite?
That being said, I like
Severine Charlotte.
I'd also like Sévérine Nadège, but that's probably way too French, right?