Isaac Davis Genealogy

I'm some how related to Isaac Davis from George Hueu Davis. If anyone out there can help me with filling in my family tree, I would greatly appreciate it. I know it's a lot of work, but I live in Chicago, IL and have a hard time getting back home to go to the Bishop Museum to collect information. My mother's name is Florence Davis, born 19 Feb 1927, in Honolulu. Her father's name was John H. Davis, he died in 1955, in Honolulu, his first wife's name was Fanny Davis who's from Portugal. John's father's name was James Davis, died 1831, at Lahaina, Maui, when he died he was a pastor. From here I don't have any information to really connect our family to Isaac Davis. My mother and uncle told me we were related to Isaac Davis. Where did they get this information from, I don't know.
Please help me find my ohana. Thank you in advance.