SG student pass rejected

I need some advice.
I am a Singaporean my wife is from Malaysian she was divorced  with one child. We are married and I applied the student pass for her child as a sponsor was rejected by ICA.
iCA would not have the answer of  why  rejected student pass. Did I miss out anything during the submission?

It is impossible, fromthe verylimited information you gave, to tell whyyour application was rejected.
Some ideas might be too low income, mistakes in the application, not a full-time course at a recognised institution, or maybe the mother should apply (not you). You probably have to ask ICA, not us!