You were Matt's kid. However, you didn't meet Matt until you were older. He didn't even know you existed. Therefore, Foggy didn't know you existed.

One day, during the Frank Castle case, Matt was watching you while your mother dealt with whatever she was doing. So, he took you to work.

"Matt, good to see you're actually here," Foggy said. He froze when he saw you. "Uh, who's this?"