I'm only going to talk about one of the three stories in Shazam! 11 (March 1974), which is the first Marvel Family story since DC launched the characters.
Maggin is joined by Kurt Scahffenberger who, incidentally, was a major artist on Mary Marvel and Marvel Family stories back when Fawcett was publishing them, for a Christmas story. Uncle Dudley, Mr. Tawky Tawny, and Sterling Morris all get cameos in this tale, as does Sunny Sparkle. Although we do not see it, you know Sunny is going to walk out of the Christmas party with everyone's presents.
Sivana and his two evil children, Sivana Jr and Georgia, are executing a plan to ruin Christmas by making time run more quickly, so it passes super fast. When Billy Batson, Mary Batson and Freddy Freeman see the clock spinning frantically ahead they spring into action as Captain Marvel, Mary Marvel and Captain Marvel, Jr.
As the story is only seven pages long, it doesn't give the three much of an opportunity to do anything individually. It does take all three of them to hold back Sivana's clock and allow time to pass as normal.
I am not sure whether I love or hate the touch of having the handicapped Freddy Freeman say the Tiny Tim line, God bless us everyone.