I have identified my spouse name when asked marital status. Now in family details it says " Please mention family members not identified in the application".
Mention is again. I don't think they will reject your application because you mentioned your spouse twice. On the other hand, lack of information where they want it is tricky.
Does it? I think you wrote that they are asking for members not identified in the application. The way I read it, your wife is not identified in the application (as an applicant), therefore I see no reason why you should not include her.
I did not list it again, as my spouse will accompany me when we land - clearly it says 'not identified in the application'. If your spouse is not a co-applicant in your PR application, it might make some sense to list it again, otherwise I'd suggest do not.