Responses
I wanted to answer this earlier but couldn't think of any at the time. I think this story is very similar to what you're looking for!
http://www.mangago.me/read-manga/the_archmage_s_daughter/
anything similar to http://www.mangago.me/read-manga/the_twin_siblings_new_life/
twins reincarnate together as illegitimate royalty, get abandoned and abused then once mom dies dad comes back to get them