Self-employment taxes

My daughter is doing some tutoring. She gets paid in cash or checks. She wants to do the right thing and pay quarterly state and federal self-employment and income taxes. Being that estimating and paying taxes can be a complicated thing to do, I was searching for some software or app that can make the process easier. I found surprisingly little out there. Quickbooks is the closest thing that helps you pay your federal self-employment tax but not really your income tax and for state taxes, you're own your own. I was wondering if anybody else has had the problem and what you did about it.