Credit card? No income??

I want to get another credit card to help build my credit. I have good credit, but I only have one credit card reporting to my credit. So, by default my credit score doesn’t go up much if at all because I don’t have a lot of availability. The credit card I do have I only charge for gas and/or groceries and pay it off every month.

My problem is that I have no taxable income. I babysit for a friend and am paid cash (not enough to have to tax though, I’ve checked!). I am able to pay for another card, as I budget well and my husband makes most of our money anyway. But would I even get approved? Has anyone else gotten a credit card with no job??