I believe the person you were attempting to reply to, "Jeanny," is most likely Jean Sain who has posted a very detailed family tree on Ancestry including the Nummer information. You might search for that tree and attempt to contact her through it.
Since reading your post, I have been attempting to find information on Henry and his son Joseph. As yet, I have not tracked them down. I do however have quite a bit of info on the Peter Kettern and Charitas Nummer descedents. They actually settled in Fort Wayne, IN not Pennsylvania. However, one of their children move to Erie, Pennsylvania. So I do believe they may have had family there.
I am related to this family through the Schmitt family. Heinrich's mother was Agnes Schmitt who was my 3G aunt. I have found a great deal of recent data on line about births and marriages, but not any death records. I would appreciate any info you might be willing to share. I will be happy to provide the Indiana info I have if you are interested.