Didn't she say that she (https://en.wikipedia.org/wiki/Rhoda_Morgenstern) has a brother too on The Mary Tyler Moore Show, yet he is also nowhere to be seen (https://www.sitcomsonline.com/boards/showthread.php?t=410099) on Rhoda.

Never a brother mentioned on MTM Show but, yes originally in the season right before Rhoda starts, there's that episode with a Debbie who I guess was just blah, but so glad they found Julie Kavner when the series started in 1974!

Rhoda Lost a Sister to Chuck Cunningham Syndrome, But Don’t Worry, She Gained Another One (https://popculturereferences.com/rhoda-lost-a-sister-to-chuck-cunningham-syndrome-but-dont-worry-she-gained-another-one/)

Yes! On an early Mary Tyler Moore show episode it was mentioned that Rhoda had a brother named Arnold !;)

I've always wondered if, since the Morgenstern women had phonetically similar names: Ida, Rhoda, and Brenda if Debbie was actually just a nickname for Debra?

And maybe like her sisters she shared a middle name too... Debra Faye :happyface

She moved to Minneapolis