Based on the information that you provided, it does not appear that your mother can claim you as a dependent. In order for a parent to claim their child as a dependent, they have to not only meet the relationship test, they also have to meet the support test. Support includes amounts paid for food, shelter, clothing and medical. Since the majority of your support for food and housing comes from other sources, your mother would not be able to claim you as a dependent on her tax return.
For additional information, please see: TurboTax: Who Can I Claim As A Dependent