Wrasse Sex Change Time?

[rastaangel]

I know that fairy wrasses like my rhomboids and flames will change sex when the dominant male dies or goes missing.
My question is regarding the time line for this to happen
I had a super male/female pair of rhomboids in QT but the female had a panic attack when I turned on my kitchen lights late at night and was KIA.
IF I decided to get another female and kept her as the only rhomboid in QT with other fish would she start the transition to a male in QT or will she stay female being as tho she would be the only one in there?