I adore both
Felix and
Felicity, but they obviously don't work as sibling names.
Lee as a middle name is too... confederate to me, but I enjoy the sound.
Marianne is charming, and it makes me think of
Marianne Ihlen.
masculine list:
https://www.behindthename.com/pnl/191050/124079feminine list:
https://www.behindthename.com/pnl/191050/124080