Praxedes (Πραξιδίκη) is from the Greek praxis (action) — "active doer." Saint Praxedes (2nd c.) was the Roman virgin saint, daughter of Senator Pudens, who hid Christians and collected the blood of martyrs.
Praxedes 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 Praxedes reduce to 2, The Peacemaker. This is a traditional interpretive system, not a factual claim about the name.