Doing Taxes: Why is our total rebate roughly the same as when I was single?

I've been doing my own taxes for a couple years on Turbotax. This year though I got married. I already had a child going into marriage which I have 100% of the time. I did our taxes, but haven't finalized the filing because I think I may be incorrectly figuring it. Together (roughly 44,000 income combined) we are still only qualifying for the same amount of money back that I reasonably would have gotten alone. I am wondering why this is, and if we could benefit from filing seperate instead of jointly. Also, I rely on this money to pad my savings for unexpected expenses that always seem to come up (medical, car mostly). How can I figure out my "share" since most of these deductions come from my qualifications (child, childcare)? If I start my Turbotax file from the beginning and change the filing status will it save the other work I've already put into this thing?