In 2013, the AGI floor for someone under age 65 is 10% of AGI. The 7.5% floor applies to those 65 or older. Since it is you, and not your mom, who is taking the deduction, you must use the 10%-of-AGI floor.
A retirement plan that pays benefits based on contributions to individual accounts, plus accumulated earnings. Contributions are generally based on a percentage of salary or earned income.