I didn't find any early Censuses with June and her parents. You can try to order a copy of her birth certificate from the San Francisco Assessor-Recorder, www.sfassessor.org/
but they might charge you a fee for each birth date.
June married Henry Hambly in San Francisco, San Francisco on May 16, 1901. Source: from a private family tree in Ancestry.
I'd try to find a copy of her marriage certificate to Henry Hambly. Contact the Assessor-Recorder to order.
In 1910 Bessie M. Hambly was living in San Francisco, San Fran Co.
Bessie, b. CA, 28, married 10yrs, no children, proof reader publishing house.
Bessie M. Hambley and Henry Hambley divorced April 27, 1910, San Francisco. Source: same as above.
In 1911 a Bessie M. Hambly was living in San Francisco, widow, residence 1791 Pine. Source: Crocker-Langley San Francisco Directory, p. 356; U.S. Directories 1821-89.
In 1914 Mrs. Bessie Hambly, Residence=724 Leavenworth, San Francisco; Crocker-Langley San Francisco Directory, p. 411.
June Elizabeth Boyle
Born: 24 June 1884, San Francisco
Spouse: Allan M. Boyle
Residence: Hilo, Kauai, HI
Passport issued 23 July 1923. Source: U.S. Passport Applications 1795-1925.
In 1930 June Elizabeth Boyle was living in South Kohala, Hawaii, Hawaii Territory.
Moses Kapoi, HA, b. HI, 67, laborer cattle ranch.
Luka, wife, HA, b. HI, 64.
Elizabeth Kaaekuahiwi, sisterlaw, HA, b. HI, 21, single.
June Elizabeth Boyle, OC, lodger, b. CA, Widow, trained nurse cattle ranch.
Do you have a copy of her obituary? The Napa County Historical Society, napahistory.org/contact.html copies obituaries for a fee.
The Napa Valley Genealogical and Biographical Society, napavalleygenealogy.org/ also provides copies for a fee. They might be able to tell you how long June lived in Napa Co too. They probably have Napa City Directories too.