First of all, you can always petition your mother. The I-130 petition approval is only about establishing the truth of the relationship. It has nothing to do with your income or anything else. It's at a later stage, after the petition is approved and when she goes through Consular Processing, where they will need an Affidavit of Support from you the petitioner, and where a joint sponsor can be used if needed.
Second, when it comes time to need an Affidavit of Support, it's okay even if you (the petitioner) and your household don't have any income. If your household income and/or assets is insufficient to meet the requirements, a joint sponsor whose household does meet the requirements can be used.
Third, debt is not considered for Affidavit of Support purposes. Only income (and optionally assets if income is insufficient).