Ross and Jack in Titanic were not real. It was a fictional story about the romance between two young people who met on the Titanic. The story was influenced by historical facts and literary traditions, but it did not mean that the characters and plots were real.
They're not the same. Everett Ross and Thadius Ross have separate identities and storylines in the comics. Their powers, if any, and character arcs are completely different.
I'm not sure specifically who 'ann b ross' is just from this phrase. It could be an author. Maybe it's someone who has created works within the realm of 'fantastic fiction' which might include elements like magic, otherworldly beings, or extraordinary adventures.
The Betsy Ross story is based on historical accounts and tradition. However, historians continue to debate and research certain elements, so we can't be completely certain of its absolute truth.