At those rates, I wouldn't be in a hurry to pay anything off, as history suggests that investing your money will provide a greater return (FWIW, I grew up when 9-10% mortgages were standard, and I always prepaid, because that's what my folks did. But when we refi'd into the exact same mortgage you had, I said, wtf, why would I want to pay this off early? Because if the market doesn't return better than 2.875% in the next 15 years, we have much more serious problems and I can forget about retiring period!).
That said, if you are cautious, I can't disagree with getting the student loans paid off. I am all about security, so for me, "what happens if everything goes into the shitter" is a driving question (learned the hard way, a/k/a DH laid off when I was 8 mos. pregnant). If the worst happens, you can sell your house to pay off the mortgage; you can sell your cars to get out from under the car notes (assuming you're not upside-down); you could even declare bankruptcy if you ran up massive CC debt. But those student loans are not dischargeable and will stick with you until you pay them.
So if you were me, I would get rid of the student loans, pay the cars and mortgage on schedule, maximize your tax-advantaged accounts, and throw all the extra at a post-tax account. Then, by the time you are ready to have a kid, you will have $900 less in current expenses (student loans and car loans gone), and a nice pot of money that can help cover those annual property costs if you need.
