The IRS has strict rules and guidelines on who can be claimed as a dependent on your return. Most times children are unsure if they are able to claim their parents as a qualifying dependent, Turbo Tax has a a great FAQ that provides the guidance and checklist to see if your mom would qualify. Click here: https://ttlc.intuit.com/community/credits-and-deductions/help/can-i-claim-my-parent-as-a-dependent/00/26139
If she does qualify, you will be able to enter her as a dependent on your return, the program will guide you through how to do that.