Per the 1880 Census for East Earl Township in Lancaster County, PA;
John B. STOVER (42) with wife Catherine (37) and children: William (18), John J (13), Anna (11), Harry (7), Fanny (5), Charles (4), Emma (2) and Milton (2) are listed as dwelling 430 on pg. 172.
The next entry in dwelling 431 on pg. 172 is the household is the of Michael WOLF, consisting of: Michael WOLF (64), Lydia (60), Ann (20), Mary (21), Isaac (18), and Catharine (71) listed as sister and feeble. These are the parents of Lazarus WOLF, who is listed in the same census on page 176.
In my head, I wondered how John J. STOVER would have met Mary Ida WOLF. I suspect that she would visit her grandparents, Michael and Lydia, and in the course of this visiting had opportunity to meet the neighbors on the next farm and their kids - the John B. STOVER family, including son John J. STOVER. I seriously doubt I will ever know for sure, but this is a reasonable guess.