Hi Kathy: I think the JOHN SEPTER born 1833 that is listed on the 1850 Census with MARY SEPTER born 1815 is: JOHN HARVEY SEPTER b. 15 Sep 1833 m.ANNA A. HOKES 24 Jan 1871 John H. SEPTER d. 4 May 1905 buried St. Anthoney Cem. Emmitsburg.
I have really no idea who the JAMES SEPTER b.1839 is listed with Mary Septer on the 1850 Census but I do have a JAMES F. SEPTER who was b. MD that died in Andersonville Prison during the Civil War and he was about the right age to be serving during that war and he disappears from any records I can find after the war.
The MARY JANE SEPTER I simply don't have any information about.
I believe there is a good possibility that they are all the children of JACOB SEPTER and ANN McLANAS.
How MARY SEPTER b.1815 figures into the picture I have no idea.
Sorry I not able to send you any documented proof of any of this but maybe something in the information might be of some help as a guide.
I noticed in the 1850 Census in Frederick Co. MD there is still another JOHN SEPTER b. 1815 living with JASPER PEDDICORD and his wife ELIZABETH (daughter of Frederick Septer b. 1762) just to confuse matters a little further. What a MESS !!!!!!
Certainly you may contact me if you would like firstname.lastname@example.org and I will do my best to help you in your research.