A few of them got no romance
Mother/daughter - From Maid to Mother
Mother/daughter - I'm A Stepmother, But My Daughter Is Just Too Cute!
Mother/daughter - I Raised Cinderella Preciously
Mother/daughter - Moto Kizoku Reijou de Mikon no Haha Desuga, Musumetachi ga Kawaii Sugite Boukenshagyo mo Ku ni Narimasen
Mother daughter - Éminence Grise Female Lead Is Trying to Make Me Her Stepmom
Mother/kids - A Stepmother's Märchen
Mother/kids - Charlotte Has Five Disciples
Mother/kids - I Became the Mother of the Strongest Demon Lord's 10 Children in Another World
Father/kids - Peerless Dad
Father/kids - Isekai Yururi Kikou ~Raising Children While Being an Adventurer
Father/kids - Eleceed
Father/son - Goblin Dad
Father/son - Beezlebub
Gender Ambiguous - Elqueness
Gender Ambiguous - Rimuru (childcare is not focus)
Multiple Guardians - Saihate no Paladin
Multiple Guardians - Omniscient Reader’s Point of View (a stretch)
I can’t think of any more. I know I’m missing some. Anyway, I kept it fantasy/Isekai. There are more but they kinda slice of life. For this genre there are more different gender ones. If the usagi drop undertones are what’s bothering you I know some wholesome ones.
I kinda wish there was one that was a son and a father. It’s always father daughter or mother son