I have some information on Gamache`'s on tribalpages.com
massengale.tribalpages.com
visitor password: massengale
Search and see if there is anything that helps you.
Rene`

A French Canadian relative bridged the gap between the French in 1600 in France:
Merged ged with E. L'Heureux ged at:
http://wc.rootsweb.ancestry.com/cgi-bin/igm.cgi?db=gamachelheureumg

My basic list of 41 people without Edith's ged is:
Gamache, Alfred
abt 1867 - St. Louis -
Gamache, Amelia Nellie
Sep 1889 - St Louis, St Louis, Missouri, United States 17 May 1941 - Vinita Park, St Louis, Missouri, United States
Gamache, Amelia Nellie Newell
Sep 1889 - Missouri -
Gamache, Auguste I ( Augustin)
18 JUL 1774 - Historical New France 03 SEP 1830
Gamache, Auguste Ii
27 MAY 1797 - St Louis, St Louis Co., Missouri 1859
Gamache, Blanche
ABT 1884 -
Gamache, Charles R.
31 May 1887 - Missouri City, Fort Bend, Texas, United States 8 Feb 1910 - St Louis, St Louis, Missouri, United States
Gamache, Cora Lee Annette
10 Feb 1869 - St Louis, St Louis Co., Missouri 9 Jul 1933 - Missouri City, Fort Bend, Texas, United States
Gamache, Edward Eugene
abt 1939 - Los Angeles, California -
Gamache, Eleanor Frances
12 OCT 1933 - Los Angeles, California 03 DEC 1999 - Westminster, Orange County, California
Gamache, Eulalie
abt 1869 - St. Louis -
Gamache, Frank
abt 1860 - St. Louis -
Gamache, Georg
abt 1858 - St. Louis -
Gamache, Girard Albert
25 Jul 1879 - St Louis, St Louis Co., Missouri 1936
Gamache, Harry
1877 - St Louis, St Louis, Missouri, United States 21 MAR 1929 - St Louis, St Louis, Missouri, United States
Gamache, Irma
abt 1932 - California -
Gamache, Isabelle
08 SEP 1870 - St Louis, St Louis Co., Missouri 11 NOV 1871
Gamache, Isabelle (2)
ABT 1882 - Died In Infancy -
Gamache, James
30 OCT 1917 - St Louis, St Louis Co., Missouri 18 MAR 1980 - Los Angeles, CA
Gamache, Jean-Baptiste
1734 1805
Gamache, Jean-Baptiste
1704 1748
Gamache, Jeanette
abt 1864 - St. Louis -
Gamache, Joseph
10 MAR 1915 - St Louis, St Louis Co., Missouri 26 MAR 1961 - Los Angeles, CA
Gamache, Josephine Carpenter
24 DEC 1880 - Missouri 24 FEB 1953
Gamache, Julien I
10 JUN 1823 - St Louis, St Louis Co., Missouri -
Gamache, Laura
ABT 1872 - St Louis, St Louis Co., Missouri -
Gamache, Lavonne M
April 16, 1956 - Los Angeles County, CA -
Gamache, Louis
1678 1745
Gamache, Marie E
3 May 1913 - Los Angeles, California 13 Feb 2002 - Ewa Beach, Honolulu, Hawaii, USA
Gamache, Nicolas
1639 1699
Gamache, Polly
- -
Gamache , Richard A
09 Jul 1960 - Los Angeles, California, United States -
Gamache, Richard F.
10 JUL 1908 - St. Louis, Mo. 1972
Gamache, Richard George
19 DEC 1936 - Los Angeles, California 18 FEB 1972 - Los Angeles County, CA
Gamache, Sylvan
abt 1862 - Stlouis -
Gamache, Sylvester
21 JAN 1911 - St Louis, St Louis Co., Missouri 05 DEC 1977 - Los Angeles, CA
Gamache, Vincent L
18 Nov 1961 - Los Angeles, Los Angeles, California, USA -
Gamache, Vincent Lucky
02 Feb 1987 - Los Angeles County, CA -
Gamache, Virginia
abt 1931 - California -
Gamache, Walter Ferdinand
08 NOV 1874 - Missouri 21 Jun 1956 - St Louis, St Louis, Missouri, United States
Gamache, William
23 AUG 1846 - St Louis, St Louis Co., Missouri 24 May 1923 - St Louis, St Louis, Missouri, United States

Looking at that and the Edith L'Heureux ged, your family isn't obvious in the connections?
Roger Bagula