Hanging In to The Brady Bunch Variety Hour

Hanging In (and Maude's) Maggie Gallagher crossed over onto Soap for 10 episode

The first All in the Family spinoff character was Maude. Maude was Edith Bunker's cousin.

The Jeffersons' George Jefferson was the second All in the Family supporting character to spinoff onto his own show.

The Jeffersons family appeared on the final episode of Fresh Prince where they purchased the house from the Banks family.

Diff'rent Strokes' Arnold and Mr. Drummond considered buying the home of The Fresh Prince of Bel Air's Banks family.

Hello Larry's Larry Alder crossed over onto Diff'rent Strokes for 3 different 2-part episodes

Hello Larry's characters were mentioned on Hi Honey, I'm Home!.

Should be The Brady Bunch. The Brady Bunch's Alice crossed over onto Hi Honey, I?m Home!

Both spun off from The Brady Bunch