Those words leave open the prospect that she is seeking an annulment not a divorce and an annulment creates the legal fiction that there was no marriage . I have no clue what kind of problems that creates for citizenship purposes but I'd sure want comments from a skilled immigration attorney on the so called agreement PRIOR to execution of same.
What are the relative earnings/assets of the 2 people involved?
I doubt a divorce 6 years after a marriage looks like a sham for green card / naturalization purposes
But a written agreement of lack of consort and an annulled marriage might suggest the deal was about green card/ naturalization ?
She is probably entitled to a divorce in NJ
She is not entitled to an annulment if that unsigned agreement is a misrepresentation of the facts
I don't know but you better find out?