Betsy is the English diminutive of Elizabeth — from the Hebrew Elisheba ("my God is my oath"). Although the historical evidence is debated (the story was first published in 1870 by her grandson), Ross has become the embodiment of the citizen-craftswoman in the founding mythos of the United States. Fox Show (2013-2014). Saint Betsy is the same as Saint Elizabeth.
Betsy does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Betsy reduce to 8, The Visionary. This is a traditional interpretive system, not a factual claim about the name.