Is it even possible for a bone to break with a hammer?

It is indeed possible to break your own arm with a hammer, however it certainly wouldn't be easy.

If she really did break her own arm intentionally, then there are two primary concerns:

1) Why is she self harming?

Perhaps she should be in regular therapy to help her deal with this self loathing or attention seeking.

2) Is it possible her bones are brittle due to excess dieting, insufficient nutrition or calcium leaching?

Of course she could have said this just to be dramatic. Your suspicion that she fell and broke her arm may well be correct. Medical staff should be able to tell the difference between breakage due to a heavy fall and impact from a heavy object. I'd be concerned about their level of expertise if they cannot.

Either way, there are still psychological issues to be addressed.

As her friend you may need to guide her through this troubled time. Don't be afraid to ask for assistance from a school or guidance counsellor. You don't necessarily have to provide her name. Just ask on her behalf and see what the counsellor has to say.

Possible, but not easily done. The body swells up the area and makes it super painful which prevents further damage being done.

Depending what kind of fracture she has is whether i'd believe her, if its incomplete and very very bruised then I'd be inclined to think she did do it. If it was a complete fracture that was an accident

not possible and i know as i have tried many times

Yes.

Yes it's possible

Yes

OH YEA !!!!!