It's a slow burn and the husband is sick and bedridden for most of it. A rich newlywed young noblewoman's older husband gets sick and its virtuous of a lady to take care of her sick husband but the noblewoman doesn't know much about nursing people so she enlists the help of a blind beggar's daughter to teach her how to take care of the sick husband. Once more it's a slow burn they don't end up together in the end and there's no smut. It's mostly plot in regards to the political and social drama coming from the historical time period as the women have to deal with sexism and classism.
https://www.mangago.zone/read-manga/her_shimcheong/
https://www.mangago.zone/read-manga/this_love_that_won_t_reach/ Not exactly what you are looking for but still it’s a good one
https://www.mangago.zone/read-manga/let_s_kill_your_husband/
Have you read this yet?
I want some yuri recommendations where mc is married to a man but is in some sort of relationship w another girly?