Following her split from her second husband, Mia continued to expand her brood. In 1980, she adopted Moses Farrow, a 2-year-old from South Korea. Moses has cerebral palsy, and he works as a licensed family therapist in Connecticut. 

Her adoptive daughter, Dylan Farrow, was born in Texas in 1985.

Once Mia and Woody embarked on their relationship, both Moses and Dylan were formally adopted by Woody in 1991. Dylan is a key figure in the HBO docu series Allen v. Farrow, as she discussed the sexual abuse allegations against her former adoptive father.

Dylan and her husband have a daughter named Evangeline.