My 3 suggestions:
1. For piece of mind, stay on the ground in your own vehicle/RV. You'll want to be there in an emergency, and you'll want the option of being able to stop and take care of things as needed. In a train/bus/plane you can't do that. Don't think of the travel time, think of the tales of adventure you can share down the line
2. Contact as many charities as possible and plead your case. Are you guys (or your families) affiliated with any churches? They have money or can collect some for you.
3. Speak to your employer. I know you are independant contractors - but were it not for them having you work OOT so late in your pregnancy you would not be stuck in CA with the baby. You and Paul have been working there for years, right? They may just kick you down some money and right now you can't afford not to ask...good luck!