I think I can help as Henry & Elizabeth were my Great Grand Parents.They had three children, Lillian, Mabel & Arthur.Mabel did not have any issue.Lillian married Howard Palmer and had four children, Donald, William, Grace and one other duaghter.That is about the extent I know of that line but I could find out more.
Arthur Henry married Idella May Selwah (1904-1979) and they had ten children, one of whom died in infancy.
Oldest son was Kenneth Beecher Prall (18-4-1925 to 1995 or 1996).He married Mildred Baltzer who is still alive.They had five children: Susan May, Kenneth "Allen", Laurie Richard, Carol Marie (11/07/55) and Gail Joan.Allen had seven children, Dianah Marie (22/10/76), Martha Jayne (27/01/89), Melissa Elizabeth (19/11/82), Andrew James Kyle (08/04/81), Laurie Leanne (28/04/79), Allana Faith (26/08/87) and Matthew Nathan (17/09/85).Laurie has two children Dora Fay (22/03/73) and Douglas Albert (26/05/70).I am unsure of the next generation of Prall's from this line other than I think they have been prolific.
Donald Franklyn (14/01/27) married Marion Pineo and they had two children, whom may have been adopted.Peter (29/10/61) who has two children and Rickey (30/10/58 - 28/9/78).
Robert "Henry" married Kay Balcolm and had ten children. David "Glen" who has a daughter Nichile Lynn Faulkener-Prall; Daniel who has two children Deanne and Bradley Prall; Phillip; Steven who has three children Tracey Lynn, Lee and Ian Steven; Wendy; Lisa; Heather; Timothy; Randy and daughter Sarah; Robert.
Mabel Elizabeth (07/05/33)
Ruth Marguerite (06/12/37) who married Donald Frank Conrad, who has provided much of this information.
John Phillip (my father) (15/03/1939) who married Charlotte "Elaine" Marshall and they have five children:Craig (18/08/62), with two children Jessica Ruth (18/01/93) and Jonathan Craig (16/06/96); Alyson "Jill" (25/2/63); Roger (17/07/66) - no children; Ian (04/05/70)with one son Sean Stevenson; Paul (04/05/70) with two children Hayley and Rachel.
Mary Kathleen (19/11/41 - 5/1/89).
David Arthur (08/10/43) with three children Patrick (15/01/67), Sheila (16/04/68) and Angela (26/05/71).