Roberta was Howard Stark's (Tony Stark's father) lawyer and the executor of his will. After Howard Stark's death, Tony was sent to live with the Rhodes family so he can go to school and have a normal life. Roberta was named Tony Stark's legal guardian.
In Meltdown, when Tony has been struggling and neglecting his schoolwork, Roberta shows him his father's will, which tells him that if he can't maintain an acceptable grade point average, then he will lose control of Stark International.
Roberta Rhodes was present when the team's secret identities were shown to the world. At first she was mad for hiding this from her, but then she gives Rhodey a big hug.