It's a simple decision, choose which gets you more; DCC or claiming your mother's dependent exemption. For most people, it's the DCC. Since you have two kids, pay her $6000 to get the maximum benefit.
To verify which way is best, you can use this tool to do trial returns, each way. <a rel="nofollow" target="_blank" href="
https://turbotax.intuit.com/tax-tools/calculators/taxcaster/">https://turbotax.intuit.com/tax-tools/...>
This assumes your mother has no other reportable income, and will not have t pay any tax on the income. Social Security is not taxable for low income people. There is a small risk that your mother may have to deal with an IRS inquiry; but it should pass scrutiny.
