To clarify, I was referring to the Sandelin child in the following census, which I had earlier posted for you here, in this thread of yours:
1860 Greenfield, Monroe, Wisconsin Post Office: Tunnel City Mary Lowe 53 born about 1807 Pennsylvania <---------Mary William H Lowe 20 John C Lowe 17 Cyrus L Lowe 15 Mary E Lowe 13 Susan Sandelin 8
This Mary, above, is said to be Mary Sandelin (or similar spelling of that name) by the descendant of John C Lowe whose post I pointed you to. She is the widow of William; she and William are the parents of a David who might be your David (and probably is your David). The original handwritten census document does not shed light on who Susan Sandelin is or why she is living with Mary.