A dialogue cut from ROTJ states that Luke's mother indeed was pregnant the same time his father left. Should I consider it canon and add it into the timeline? (it also states Owen is Obi-wan's brother).

BEN

When your father left, he didn't know your mother was pregnant. Your
mother and I knew he would find out eventually, but we wanted to keep
you both as safe as possible, for as long as possible. So I took you
to live with my brother Owen on Tatooine... and your mother took Leia
to live as the daughter of Senator Organa, on Alderaan.