Hi Janine,
I think your best strategy is to start at the beginning, and to enter as much information as you have, so others can help to build on it.
I had to track down your late husband's great grandmother Leona Rackley here:
https://www.wikitree.com/wiki/Rackley-249
You mentioned she had a sister, Jennie. However, Jennie does not have a profile yet, and of course, Jennie's husband William Columbus Lattimore is not connected yet either.
If you could enter what information you have and point us in the right direction, then it would really help to do further research off of.