Full title: Spider-Man: Brand New Day (2026) made me realise I must be getting old because the first time I saw Aunt May 24 years ago in Spider-Man (2002) she just seemed like a nice old lady, but now I am starting to appreciate that she is still very attractive.
Had to look it up, Tomei is 61 currently so was likely between 60-61 during filming. Still, she looks absolutely stunning. I would assume late 30s, early 40s from the OP.