I'm looking for historical dramas where there's a very positive relationship between family members. Not necessarily the whole family, but siblings for example. Also their relationship doesn't turn sour as the story progresses and it should be at least somewhat relevant to the plot, not just a quick sidenote. I'm also open to suggestions about dramas with relationships between characters who aren't blood-related but become like a family. For example, in The Long Ballad the main character had a young boy that became almost like her little brother. 

Please, when you suggest a show, tell me which family members have that kind of a relationship in the drama. Thank you. :-) 

Love and Redemption (FL and her sister. Very close, loving, and never damaged in the entire drama)

Love Like the Galaxy has a nice sibling relationship between the FL and her brothers (but a horrid one between the FL and her mother)

The Untamed (Lan Zhan and his brother Lan Xi Chen, Wei Wuxian and his sister Jiang Yanli both have very good relationships. There's also some more complicated family relationships.)

Iljimae  - ML + (adoptive) father

Rebel: Thief Who Stole the People   - ML + his brother, father and all found family

Warrior Baek Dong Soo  - ML + his guardian/father figure ( also for SML),  SFL + her father

My Country: The New Age  - ML + his sister

River Where the Moon Rises - I personally really liked the relationship between the FL and her little brother. There's also the twins' relationship.

Alchemy of Souls - ML and his maid, who is like a mother to him.