You probably need to file a schedule C business on the personal return, and have her pay self-employment taxes. If 1099s are received, then they just flow into the sch C, and any expenses are deductible. Depending on the amount earned, she may or may not receive 1099s.
Given the simplicity of what she's doing (from an accounting standpoint), keeping track of income and expenses in excel or similar should be adequate. For that matter, you'd be surprised the number and size of businesses that run out of a personal checking account and a shoebox of receipts. You'd be ahead of most of the them, keeping track in excel.
IRS allows cash basis reporting, which is most likely the best option for you.
This route avoids legal costs, accountant fees, and excess complexity. If the blog gets really big, then revisit the structure.
Things to research and consider:
-Home office (do you qualify?)
-What expenses apply? I would expect a portion of your internet costs, website related fees, advertising costs, etc.
-Solo 401k as Gin1984 mentioned
Doing that, you might be able to reduce the income down so that you don't pay much, if anything in taxes. And 1/2 of the Self employment taxes are deductible on the 1040.
This is completely doable on your own. The various tax prep softwares can handle this stuff, you might just have to get the next level up on the software.