Doonesbury by Garry Trudeau for September 26, 1972
Transcript:
Clinton: Joanie! Joanie! I've come for you, baby! Zonker: Forget it, man! She's staying with us! Go away! Clinton: Joanie, listen to me, honey! I've got a tape recording, honey - it's of our youngest daughter. I'm going to play it now, Joanie! Mommy, mommy, come home to us! Please, mommy! Zonker: That's a cheap trick, mister!
Joanie presumably did have more than a single offspring (JJ)