User blog comment:Gourgeist/Shingeki no Kyojin Chapter 64 Review: Welcome Party/@comment-199.79.169.163-20141213180008/@comment-99.120.99.33-20150105060450

In a previous chapter, Mikasa mentioned that her father met her mother in the forest that he escaped to. However, she knew of her mother's persecution. Being the last full Asian known in the walls made Mrs. Ackerman(name still unknown, but I'm guessing she is of Japanese descent), a high value target for traffickers.

Her father's persecution is still unknown, but if you're right about his involvement in the failed revolt against Rod, then he has direct family ties to Kenny that would make him, Mikasa's uncle and Mr. Ackerman's brother.