Dielman and Agnes did have a daughter named Gertrude but she would be too old for your Gertrude. Gertrude Schumacher is Agnes' sister. Dielman and Agnes also had a son named Dielman. I suppose it is possible that their son married his aunt Gertrude. (not likely). There are many, many other Dielman Kolbs. I would be glad to share the possibilities with you but I'd rather do it by email. gabgolly@aol.com. Thanks Paulette from NM