Mileva is from the Slavic mil (gracious, dear). Mileva Marić (1875-1948) was the Serbian physicist and mathematician — Albert Einstein's first wife and only fellow physicist student at the Zurich Polytechnic. The only woman among six students in Einstein's section, and the second woman to complete the full mathematics and physics program at Zurich Polytechnic. The extent of her collaboration in Einstein's 1905 "miracle year" papers remains intensely debated — but Einstein gave her the entire 1921 Nobel Prize money as part of their divorce settlement.
Subject of Dord Krstić's Mileva & Albert Einstein: Their Love and Scientific Collaboration (2004).
Mileva 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 Mileva reduce to 8, The Visionary. This is a traditional interpretive system, not a factual claim about the name.