http://www.bbc.co.uk/news/health-16300314
They share all organs. There are two functioning brains and two spines. One heart, lungs, etc.
Let them grow up as is, remove a head to give one child a normal life?
Whewww. Hard decisions to say the least.
I know there are twin girls in the US similarly joined. They recently passed their drivers exam.
http://www.youtube.com/watch?v=VMzK6iz6uVs
Each has control over that side's arm and they have to cooperate to do two handed things but they do it.
Just hope the best for all concerned I guess.