I feel like sometimes I put too much stock in Ancestry.com. They might be the most comprehensive source, but that shouldn't be the only source one uses. I often times will check with findagrave.com, however I was still looking for more. On a whim, I decided to do some additional searching on familysearch.org, thinking it would be identical to my search results on Ancestry.com. I couldn't have been more wrong!
Through this search, I was able to find ML's grandfather's death certificate, already indexed and searchable. This gave me the names of her great-grand parents! What a find! In addition, through searching here, I have been able to find an unknown aunt. Females are harder to track down due to the last name changing when they get married, however another indexed death certificate proves that she was also related.
The information about the aunt was actually missing from the reports given to me by ML's distant cousin, so it also goes to prove one more thing: Just because someone else has researched a family member, it doesn't mean there's nothing more to find!