My mother died in February does someone need to file her income taxes?

Firstly, my sincere condolences on your loss - I have experienced this myself, albeit 17 years ago, but the loss still feels like yesterday.

To answer your question, Yes. The executor (or executrix) will need to perform this task. See the website IRS.Gov for info about this. If you mother died in 2008, then I believe you have to wait until 2009 to file for the current year. The IRS will be able to better direct you if you need more info.