I like
Laurel. It's a refreshing variant of
Laura, but it still has depth to it.
Laurel Kathleen is fresh and youthful.
Laurel Katarina is her spicier double personality, you're right.
Laurel could be a nn for something you'd like better.
Laurentine ("LOR-en-teen"),
Laurentia, Lauriane,
Lorelei,
Hannelore,
Lorena ("lor-AY-na")? Of course this might take your mn in a completely different direction.
Laurentine Katarina, nn
Laurel?