You can go to SWA online and check in at midnight before your flight. Do it as close to midnight as you can to secure your family a spot in the A group. It is easy. They will ask you to fill in your names & conf. numbers. That is it.
If you can't print them, just get yourself in the A group and when you arrive at the airport, you can get the boarding passes that will show you're A group so you can board in that first group.
Also, you all can preboard because you have a 4 yr old. I have a family of 5 and my youngest just turned 5 yrs & I have a vision impaired 9 yr old and we always preboard. We have never had a problem getting seats together.
Get your A group passes, though, just in case!
Lives4Disney
