Who is directly related?

I have a picture of their son, Robert Edward (Edd)'s headstone.

I'm looking for a list of children for John & Margaret.

Children I have:

Hallie P. Abt. 1852
John T. 01 Aug 1855 - 14 Mar 1861
William H. Abt. 1857 - 1 Oct 1881
Eliza A. 21 Aug 1858 - 28 Jul 1870
Frederick L. (Fred) 28 Feb 1861 - 29 Jan 1910
Robert Edward (Edd) 11 Sep 1863 - 4 Dec 1921
Margaret E. (Margie) Abt. 1865
Carrie J. 26 Aug 1867 - 13 Mar 1869
May E. Abt. 1869

I also found a headstone with the name of:

Mamie Bell Hennington Spencer
3 Feb 1869 - 25 May 1927

Is she May?

Karin