She sounds proper bunny boiler, who acts without thinking of the consequences..
What if one of them lit pieces of paper caught a tea towel or curtain - and it spread...
In your sitch, i would take advice.
Not only that, document everything. I would also be tempted to record or film any of this crazy stuff..
This is going to pan out badly..
When it comes to the child, you need to sort your rights and access as soon as the child is born.. But she will probably go the other way ( restrict access etc ) and say that you abandoned her / kicked her out when you found out she is pregnant..
Think how this looks from the 3rd party side.. You find out your parrtner is pregnant and ask her to leave / end it. Thats how she will sell it - and it makes you look like a really bad person, before that child is even born - hence you need to get your ducks in a row to ensure you dont look like the abuser.
The long term, there is this poor child.. Again, if shes prone to these crazy outbursts, she will probably paint you as the bad parent..
Take advice, keep evidence and keep your nerve - dont give her anything to use against you...
Previous username - Helpme123.. A name chosen at a desperate time..
Now Mr Brightside.. coming out of my cage, and doing just fine.