Mỹ (美) is the Vietnamese word for "beautiful" — from the same Chinese root. Common in Vietnamese compound names.
Mỹ Tâm (born 1981) is the Vietnamese singer.
Mỹ 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 Mỹ reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.