Oh bugger. This will be hard for them all.
I would day that Ross should stay in FT education as much as he can, and Rachel should have the baby and go back to college as soon as she can as well. Have as little time off as she can.
I had dd when I was 17 so it is not the end of the world (thouigh everyone thinks it is at the time). I was in a situation where I had no family support however, and dd's father buggered off a couple of months after she was born, so I either had the choice to work and study at the same time, or go on income support. I already felt like the scum of the earth, so back to work I went when dd was 3 months. Work was shop floor in a factory.
I then did A levels as a distance learning course (waste of time, should have gone straight to a degree with the OU). I then started a degree with OU. In the end I qualified in engineering, then got a job which paid for me to carry on studying for an MEng whilst working in the particular branch of engineering that I wanted to pursue.
It took bloody ages, I was finally qualified at 27, however I worked all the way through and paid my own way. Thank god I was young - all that youthful energy made it possible to raise a child on my own, work full time abd study.
I know it is perhaps not ideal to be out of the hoiuse FT when you have a young baby, however teenage pregnancy is not ideal either, and you have to make sacrifices frankly. If you want to be a SAHM you need the financial back up which these young teens do not have. It WILL be hard work, but there you go. That's life.
There was zero support re childcare when I was younger (dd is 14), so most of my money went on childminder etc. Hopefully Rachel will be able to go to a college with a creche, and hopefully there are agencies which can help with this planning.
Good luck to them.