Camming is a job, sure, but it's also a part of your sex life. It involves (for most of us) what arouses you, how you get off, your sexual interactions with others, your discussions of various sexual topics, etc.
WHY on earth would you tell any of this to your children? Your sex life is none of your kid's business. Personally, I wouldn't want to hear about whether my mom gets off on voyeurism, or bdsm, or buttsecks, and I wouldn't want to know if my kids do either. We're not talking about adults here, where having a frank Q/A discussion with parents about sex is completely appropriate. Telling a kid who asks "Mom, what is your job?" something like "Well sweetie, I show my nude self to people online" isn't going to make you the best role model. Would you want your 8, 10, 13, or 16 year old doing the same? Remember that kids are very easily influenced and may not understand why they aren't allowed to do the same things that makes mommy and others very happy.
You can be casual about sexuality or nudity (as Megan mentioned before concerning being naked) around your kids without being graphic.
Furthermore, whether you even (want to) HAVE children is not the business of any MFC member WHATSOEVER.
If for some reason I still felt compelled to answer, I'd say I was an online motivational speaker, counselor, consultant, therapist, (artistic) model, or any other aspect of camming. After all, the percentage of time you spend talking/posing in different positions outweighs the percentage of time you're actually getting off anyhow.
You don't have to answer every question somebody poses to you on MFC, particularly the ones asked in a nasty way. Just ignore it.
[[Side Note:]]Remember that if you plan on raising your children in a religious household without consistency (Megan, you mentioned knowing that your job is a sin, but doing it anyway) such things can be very confusing to a child. It could make them reconsider their obligation to their religion and their role in sinning altogether. "Since mommy can pick and choose what parts of our faith she follows/believes in, why can't I?" All that is going to do is raise some serious trust issues that will probably last a very long time.