I got 4 refusals on mother visitor visa. If she has her son or daughter PR or Citizen in Canada just go with Super Visa. Parents no need to show even funds and only sponsors need to prove income. Officer need solid reason to refuse super visaYou can’t sponsor her. She needs to show her own funds and even hers and yours combined is not a lot for a month long visit once you include airfare/insurance. It should not be that you are using all your savings for a visit. Property is not in her name, so not relevant. Your payslips are not relevant because it is not money in the banks and not her money. The bigger issue is that IRCC feels that she submitted unauthentic documents. Lucky she didn’t get a misrepresentation ban.
Does sister have the funds/income to apply for Supervisa? That would be the option and not include any of your documentation which IRCC doesn’t believe are real.