pia child legal

hi,

like everybody i was wondering how pia's child is legal or not and i remembered reading a long time back that when esha deol was born, dharmendra apparently begged his first wife (he is still legally married to his first wife) to sign papers whereby he legally adopted both his daughters with his wife's permission and so there are both legal. don't know the legality but i think that this is more like an adoption scenario whereby the child gets the father's name