I am afraid we may have Emily tied to the wrong parents as I've carried John and Jane through the 1860 to 1880 census records for Hempstead, Queens, New York. Although Emily doesn't mseem to appear in any of the census records she was asigned to John and Jane because of "PLACE'. That what I get for making assumptions. However, using your dates, she more corectly fits with John Van De Water b. abt 1835 -Hempstead, who married Rebecca J.m Stringham b. 23 Jan 1838, Hempstead. Emily may have been given the name "PLACE' For her paternal grandmother Jane Place. (John's mother)
If I can find more I let you know. There are a number of marriages between the Van De Water & Stringham families of that area.