Lavina A Sedwick  [Washington Sedwick / Elizabeth Koener]
b. September 13, 1840, Mercer County, Pennsylvania1,8,12
d. August 16, 1918 Mercer County, Illinois8,12
bu Mercer County, Illinois, Norwood Cemetery8
m. February 16, 1864, Mercer Co, Illinois, James R McLaughlin4 (vol A pg 89)

James Reid McLaughlin  [Henry McLaughlin / Jane Latta]
b. April 12, 1825, Pennsylvania1,8
d. December 13, 19128
bu Mercer County, Illinois, Norwood Cemetery8
m1 Nancy Jane Lossee11d
m2 Lavina A Sedgwick

Census records:

1850 PA Lawrence
1860 PA Lawrence
1880 IL Mercer

Lavina is likely actually spelled "Lovina." Lyle D Sedwick reports it that way, and it is spelled that way in the 1880 census, but the marriage record, her grave and the 1860 census report "Lavina."

James R Mclaughlin apparently married first a Nancy J [Unknown] and had at least one child with her; there is a gravestone at the Norwood Cemetery, where he and Lavina are buried, which appears to be the grave of his first wife. Her gravestone says "Nancy J, wife of J R McLaughlin, Aug 12, 1833 - May 15, 1862." This would agree with the marriage date of 1864 for JR and L. In the 1880 census they have a son Charles L McLaughlin age 19; I think he's son of Nancy.

Children:

Margaret A McLaughlin
  b. abt 1866, Illinois1
  d. 195711d
  m. Fred Wray11d
Alice M McLaughlin
  b. 1868, Illinois1,8
  d. 189558
  bu Mercer County, Illinois, Norwood Cemetery8
  m. William A McLaughlin11d
Harry Lewis McLaughlin
  b. August 22, 1869, Illinois1,8
  d. May 8, 18928
  bu Mercer County, Illinois, Norwood Cemetery8
  m. Vesta Brown11d
Cora Bell McLaughlin
  b. January 24 18761
  d. November 3, 18788 (age 2y 10m 10d)
  bu Mercer County, Illinois, Norwood Cemetery8
Dora B McLaughlin
  b. abt July 1879, Illinois1
  d. 194411d
  m. Guy Mead11d
Ray McLaughlin11d
  b. 188111d
  d. 196711d
  m. Clara McCutcheon11d

James Reid McLaughlin & Nancy Latta had 5 children: Oscar, Eliza Jane, Ella, Amanda, and Charles Lossee.11d

This information from ". Information was furnished by family members, not verified from other sources in most instances. As you can see, at least one of the names of children you had listed does not appear in this list. However, names of spouses may help make further connections. Evelyn Anderson
Sources:

1. Census records, any of those indicated.

4. Illinois Statewide Marriage Index 1763 - 1900
online at http://www.cyberdriveillinois.com/departments/archives/genealogy/marrsrch.html
This record:
GroomBrideCountyDateVol/pgLic
McLaughlin, James RSedwick, Lavina AMercer02/16/186400A/008900001797

8. Mercer County, Illinois Cemetery Records
William Dennison Chapter, NSDAR, Aledo, Illinois, 8 volumes
available on LDS Microfilm 0848589 for Volume I and 0848590 for volumes II through VIII available online at US GenWeb, Illinois, Mercer

11. Personal knowledge of family members/researchers
d. Evelyn Anderson, quoting The McLaughlin Family" compiled by Steven McLaughlin

12. Family Bible of Washington Sedwick, transcribed by Lyle D Sedwick.
Bible was in posession of Roberta Sedgwick, Edinburg, Lawrence, Pennsylvania.
She has since passed away; current location of Bible unknown.

Questions? Have more data? genealogy@sedgwick.org