Third wife of FH. She was his long-term companion, often reported as his 'wife', while he was in fact still married to his second, Emily Clayton. He did not in fact marry Nellie until 1927, following Emily's death.
Nellie and Frank had a tempestuous relationship with much genuine feeling on both sides. He of course gave her ample reason for jealousy with his habitual philandering.
You can see some pictures of Nellie on the Gallery page.