I, too, don't like the spelling
May, as that's a month it me, not a name. But, the spelling
Mae is very sweet and simple, but I only like it as a middle name. I think it's harder to pair a middle name up to it, when it's used as a first name. From your middle name choices, I like
Susannah and
Virginia, and if I were to choose a combo, I'd choose
Mae Virginia, but I don't think any of them flow.

The greatest single human gift - the ability to chase down our dreams. - "Artificial Intelligence: AI"