Well, there are quite a lot of manhwa where FL is a maid or knight ╮( ̄▽ ̄)╭
https://www.mangago.me/read-manga/i_became_a_maid_in_a_tl_novel/
https://www.mangago.me/read-manga/how_to_survive_as_a_maid_in_a_horror_game/
https://www.mangago.me/read-manga/a_capable_maid/
https://www.mangago.me/read-manga/the_villain_discovered_my_identity/
https://www.mangago.me/read-manga/the_baby_isn_t_yours/
https://www.mangago.me/read-manga/emperor_and_the_female_knight/
https://www.mangago.me/read-manga/the_heroine_wants_me_as_her_sister_in_law/
https://www.mangago.me/read-manga/as_you_wish_prince/
Any royalty setting shojo with the mc not a royal? Like the secretary one or queen Cecilia's shorts where shes a designer. I am also cool if she has a side job/hobby like Latte from miss not so sidekick.