From the brief info on the marriage of Ettie Quin and Issac Brown in St. Louis, in 1863, I think "Ettie" may be Esther Quin, born 1843 in N.Y., to John and Hannah Quin. The family lived in New Jersey, New York, and by 1860 census, in St. Louis, MO, 10th Ward.
There were 6 children in the Quin family, Wm. E., Geo. W., James N., Esther, Charlotte, and Ellen. James, 2 yrs older than Esther, was married in St. Louis, 22 April, 1864, shortly after enlisting in the Union Navy there.
I find an Esther L. Brown, born June 1843 in New York, Parents born in N.J.., widowed, age 57, living with a son, Charles W. Brown, and a dau., Irene E. McNight, and other McNight and Hentz family members, in Chicago, in the 1900 census, and with McNight's in 1910 census. Do any of these names ring any bells with your family info? If we can establish that James and your Esther/Ettie were of the same family, I have further info and a picture or two on the Quin side