Thank you for the input. It does appear that the link between the Roll and Batt families is the marriage of Mary Catherine Roll (b. 31 Aug 1907 Buffalo, Erie County, New York) and Elmer Lawrence Batt (b. Feb 1907 Williamsville, New York).
With your help, it now appears that the above Mary Catherine Roll, who married Elmer Batt, was the daughter of John G. Roll (b. 23 Jan 1877 Erie County, New York) and his wife Catherine (b. abt 1874 New York). I had previously found the note that this John G. Roll "has 4 daughters." This agrees with the information that we now have that Mary Catherine's sisters were: Helen A. Roll (b. abt 1910), Olive Ivadell (“Ivadell”) Roll (b. abt 1914), and Hazel B. Roll (b. abt 1917).
So now we can trace the ancestry of Mary Catherine Roll as follows:
Generation 1: Johannes ("John") Roll b. 10 Dec 1768 Near Strasbourg or Bouxwiller (Erstein?), Alsace-Louraine, Francem. Anna Maria (“Marie”) Klein
Generation 2: George Roll b. 3 Jan 1814 Alsace-Lorraine, France [Culture and language was German] m. Gertrude ("GERTRUDIS") ("Gertie") Jerge
Generation 3: Johannes (John) Roll b. 9 Dec 1845 Lancaster, Erie County, New York, USAm(1). Elisabetha (Elizabeth) Hammer
Generation 4: John G. Roll b. 23 Jan 1877 Erie County, New York, USAm. m. Catherine I. __
Generation 5: Mary Catherine Rollb. 31 Aug 1907 Buffalo, Erie County, New York, USAm. Elmer Lawrence Batt
The Johannes Roll (age 81) you mentioned who was living with his son George in 1850 is the same person as described in "Generation 1" above. This Johannes Roll was also my great great grandfather. Another of his children, Michael Roll, was my great grandfather.