Moving a child to Singapore

[who011]

Hi Experts,

Asking on behalf of friend again.

1. Both husband and wife are holding S pass and they are from China.
2. Recently applied PR together but got rejected (Wife main applicant and applied for husband and son)

However, they planning to move their Son (3 y.o) to Singapore, since they are not an EP holder. Is there any other ways they could do? Minimum salary for S Pass holder to apply DP need 6k, which they did not fall under the category.

Please advise.

[PNGMK]

Student Pass and study mama visa maybe.

S Pass to PR not possible.