She can't survive.
Having two flopping heads disembled, there would be a problem.
1.) The brains are slashed in two, meaning that they can't reach each other like they should, causing problems and damage.
2.) Because of her half head condition, having the head flap would be like JELL-O. This will eventually be fatal and she would die.
3.) Some 'wiring' from the brain to the body need to be in 1 piece. This will be impossible because of how she is at the moment.
Head-Split Girl needs to be taped together or else she will die. Either way, it's fatal. You still have blood aswell to worry about which would have spilled everywhere and the parts such as the skull and the eyes. Forgot to mention that anyone can stick their hand in and rip her vital organs in her head off. So no, your dream cannot be a reality. You will forever be shamed and stuck in your room.