Can I get any tax break?

At age 55, you can take distributions from your 401K retirement plan without penalty. But you will pay ordinary income tax on them unless you took your distribution from a Roth IRA. If you're under age 55, you'll pay a 10% penalty PLUS income tax on the withdrawal. You must be 59-1/2 to take distributions from a regular IRA account without penalty.

Here's a link that explains it in detail. (I am not an accountant.) Unless you can prove you are providing more than 1/2 of your mom's support, you cannot deduct her as a dependent.

moneyover55.about/od/preretirementplanning/a/401k-Retirement-Age-55-59-1-2-Or-70-1-2-Different-Rules-Apply.htm

(If the link isn't live, copy/paste into your browser address bar.)