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 portion of earnings withheld by an employer or put into a retirement plan for distribution to the employee at a later date. If certain legal requirements are met, the deferred amount is not taxable until actually paid, for example, after retirement.