im not so sure if there is, but if she is wrking n placing her child in CC, then she can apply for more subsidy thru CFAC (by CDC) if her income is lower than 1.8K.
other than that im not sure if there r, not that i heard of.
best option is the scrimp and save and not spend unneccessarily.
she can breastfeed her child so she doesnt have to spend a single cent on FM. (and milk bottles, sterilizers, etc)
diapers wise, use cheaper brands. clothes, try to get hand me downs if possible. other than that, she doesnt have to spend much.
vaccinations, i think some jabs can be taken free of charge from the polyclinic, do a check from the website.
btw, is it your sister's baby or your baby? hmmmm.