Your mom, her spouse and all her dependents 18 or under MUST be included in the application and have their medicals done. Even if they are non-accompanying, everyone must be included in your family size for LICO income purposes.
If they are listed as accompanying they would get PR along with your mom.
If they are non-accompanying then they would need to be sponsored again later anytime after your mom gets PR, but will only qualify while they are aged 18 or under.
If you intend to sponsor your mom you will need to have entire app ready to be at CIC on January 4, and hope it's accepted into the 5000 cap.
Only a spouse/common-law partner can be a co-signer.