Sibling names?

I already have a Finnegan Altair, but my style and preference in names has definitely changed over the past five years. I seem to lean towards bohemian/ nature type names, and strong mature boys names. I have some examples!

Girls:

Coraline

Iris

Lorelei

Luna

Gage

Cordelia

Boys:

Klaus

Everett

Atticus

Ellis

Preferably would like to have the boys middle name be William or Willem after a family member. Any ideas for girls middle names would be helpful too!

Our last name is 10 letters long, very strongly German sounding, and starts with a W!

The only name we’ve come up with that we both like is Klaus Willem.