This expression means
Doubsis – doube-six
Doubsis mouri nan men (yon moun).
(Someone) whose youth is past.
It’s become too late for (someone) to marry.
Pa kite doubsis mouri nan men w.
Don’t let time pass until it’s too late to marry.
Don’t become an old maid.
Doubsis ap mouri nan men w.
You’ll become an old maid.
Pitit fi Papouch la ap fè enteresant, li pa vle marye ak Ayisyen. Li panse l twò bon pou nèg peyi l. Lò doubsis mouri nan men l li va mary nenpòt avadra.
Papouch’s daughter is being cocky she doesn’t want to marry a Haitian. She thinks she’s too good for a man from her country. Once it becomes too late for her to marry, she’ll take any vagabond.
Another similar expression is "Fè dan zòrèy" which literally means "to grow wisdom tooth". It can be translated as "being no spring chicken"