Their involvement as members of the family isn't really complicated.
Rico is a robot, created by Setuh from recycled, sliced cores of her previous robots for cleaning purposes. She scrapped the idea, but kept the cleaning equipment inside of him. Now, he's just a normal family member. Sometimes, he acts like a little child. At other times, he acts like a grown-up. All of this is probably due to the cores that have been destroyed. Maybe some of them are still intact...
Brickina is just a talking brick, originally from the streets of Nairobi in Kenya. She once was captured by a couple of huntsmen, and was put in a black market, until she was bought by Byrd and Setuh. She may be brash at times, but she cares deeply for her ma and brother. Her sentience still remains a mystery however...