besides that, I still can't figure what happened that made her depart from politics.
1) Internal friction with key members of the NSP - GMS, Hazel etc. She was being used as a political pawn in a big game of Chess.
2) Constant and intense Media intrusion into her personal life. She could not handle all the negative attention.
3) Discreet smear campaign by the PAP using 2)
Here's the thing. MPs of all parties must be able to stand up to public scrutiny. You must be seen as being 'whiter than white' (pardon the pun) and beyond reproach otherwise you are finished as a public servant. Nicole couldn't handle the burden of expectation and being in the limelight 24/7 -hence she became a quitter and fled to Bangkok.