Mystery: Michael and Ann Coughlin 1860 Ohio

In trying to trace Irish born Ann Sheils who married Michael Coughlin and was known to have lived near Zanesville, Ohio in the 1860s I found this census record which could be a match for her.  Frazeysburg is about 15 miles from Zanesville.

Frazeysburg, Jackson Township, Muskingum County

Coughlin
     Michael          25  born Ireland
     Ann                21  born Ireland
     Mary A            4  born Ohio
     Margaret E      2 born Ohio

I have not been able to find any of them in 1870.  The girls would have been 14 and 12, generally not old enough to be out on their own.  

I've checked church and cemetery records -- no help there either.

Can anyone help me unravel this mystery?