Thanks for that, Daisy. Interesting news indeed!
So let me make sure I've got this right:
1. The original marriage record shows Bessie, but somebody has subsequently mistranscribed it as Bonnie?
2. It is possible for somebody to be called both Bessie and Eliza!
3. Bessie Eliza Isaac would appear to have been a spinster of this parish, aged 38, when she married in 1907.
4. Bessie Evans looks like a figment of the family's imagination!
Is that your reading of the evidence?