When Is a good time to have our second child?........?

I have a 7 month old daughter, we make about $55,000 take home a year and we don't do too bad, we have a house and cars, I do get wic which means my food for my child is paid for. I am a stay at home mom, while I do babysit but, I do get to take my daughter w/ me. So I'm having a really hard time deciding if I should just go ahead and have another child and get it over with now, while I'm staying home or if I should wait a while? PLease help! And please no ignorant answers.