Self employed status, whatever amount u declare HDB will give a discounted loan amount compare to a employed person. Not about CPF, since she need to file IRAS yearly and pay for own medisave anyway.
Example : both declare same monthly salary
1. Employed with CPF ,loan given 300k
2. Self employed , loan given can be just 150k
Don't ask us why, that is how it has been for many years.
You should had done HLE first, then add up both OA and cash saving, plus any grant, then find a resale unit within that budget.