Musuko ga Kawaikute Shikataganai Mazoku no Hahaoya - A manga about a demon mom raising her demon son. It's usually set up in comic strips around events but sometimes it has mini-arcs. The mom also has a curvy younger sister.
Ane Naru Mono - An orphan that's pinballed between families stumbles upon a elder god who grants him a wish. His wish being for her to be his older sister. Manga follows Chiyo trying to adjust to being an older sister to Yuu. Chiyo gives me Fire Emblem's Camilla vibes.
Okusan - a 34 year old house wife does cute things with sexy results. Has more housewives in it than any of the other manga's listed here. Has it's own dedicated thread but this thread could use some content.
Ashitaba-san Chi no Muko Kurashi - A fiancé adjusts to life at his fiancée's house. It's an almost-harem manga with slice of life elements, sexy things happen with typically awkward results. Some of the cast is also on the younger side. The Mangaka also makes Okusan and is part of the Okusan thread. Translation is slow because the translators have trouble getting the volumes.