Henrietta Jane Hinckley

Henrietta Jane Hinckley was my g-grandmother, born in South Haven,MI in 1837. Parents: Rodney and Jane Hinckley, also of South Haven/Van Buren County, MI.
I have confirmed that Henrietta & James Harris' marriage was 01 Mar 1855, and I have also been able to research the Hinckley line back several additional generations to England.
Does anyone have information about:
a) when did Henrietta die? I have one unconfirmed report of 1864, but am not confident of its accuracy.
b) Where was she buried? I know that her parents lie in Lakeview Cemetery in South Haven, along with her Uncle Isaac. It is also POSSIBLE that her husband James Harris, may also lie in this cemetery (in a different location than the Hinckleys.)
Comments:
- It IS possible that she is at rest at Lakeview also, but I've no indication. We intend to visit said cemetery next month and take pictures of appropriate tombstone/markers.
- The UNconfirmed report of her death of 1864 does not jibe with the birth date of their son, Albert, who was born in 1867 in Indian River, Cheboygan Co., MI. FYI, I show James Harris on the 1870 US Census as a widower in that same location in Michigan.
Bottom line: after their marriage, I have no information on Henrietta, and very little on James.
Can anyone help me to fill in one or more of the blanks??
Your help appreciated! PLease feel free to contact me directly.