Hello! I am a full time teacher in Seattle and use mystery shopping to augment my family's income. This is a very good fit for folks on a school schedule. You have tons of flexibility and the ability to make more than with most part time jobs.
If you have not done so already, check out the "new shoppers" area on this forum. It will really give you a good sense of the (quite large) world of mystery shopping. You'll find that this forum is the largest source of information about mystery shopping available. Of course, feel free to ask if you have questions. There are quite a few experienced shoppers here who are happy to share.
Hard work builds character and homework is good for your soul.