Do the Andersons have similar relatives like the Cleavers?

Well, there was Jim's sister Neva (whom he inexplicably calls Aunt Neva) who visited from some other city for the 1956 Christmas episode.

Jim has a brother who lives in the middle of nowhere, with the nearest town called Gurnee. The country cousin girl played by Susan Oliver, Jim's brother's daughter, visited the Andersons, and snob Betty treated her like dirt.

Margaret's cousin married her longtime boyfriend in a sort-of two part episode in season 1.

In two episodes the Andersons were on their way or preparing to go to Margaret's family reunion. In the first episode Margaret's Aunt Ione was to ride to the reunion with the Andersons. In both episodes there was talk of the varying relatives who attended.

On FKB, Jim mentions his father during his speech to Bud about the watch gift for his high school graduation. On Beaver, Ward frequently talks about his father; Jim, not so much. On Beaver, June frequently talks about Aunt Martha, who apparently had a hand in raising her; on FKB, we do see Margaret's parents in one episode. It's possible Margaret's parents live in Lemon Falls like the rest of her relatives, but it's not mentioned.

Bump only, to move old game down.