Sorry for your loss...
You might want to become familiar with IRS publication 559 - http://www.irs.gov/pub/irs-pdf/p559.pdf
As the personal representative you must file the final income tax return (Form 1040) of the decedent for the year of death and any returns not filed for preceding years.
Write the word "DECEASED," the decedent's name, and the date of death across the top of the tax return.
Write the decedent's name in the name space and the personal representative's name and address in the remaining space.
If a personal representative has been appointed, that person must sign the return. If no personal representative has been appointed and if there is no surviving spouse, the person in charge of the decedent's property must file and sign the return as "personal representative."
Generally, a person who is filing a return for a decedent and claiming a refund must file Form 1310 with the return - http://www.irs.gov/pub/irs-pdf/f1310.pdf .
This form will instruct the IRS to issue the refund in your name.
If she was eligible for earned income and Making Work Pay credits - you may claim them - there is no issued because she died.
Let me know if you need any help.