It is a bizarre story and if there is truth to it then it is very horrific. I don't want to point fingers but it seems that it could be a bid for attention. In which case my heart goes out to her because of the desperation she must be suffering to have to create such delusions.
A friend of mines step-sister had a miscarriage however she didn't deal with it well. A couple of months later she claimed to be pregnant with twins, had scan pictures and everything. At 9 months went into 'labour'. Her father rushed her to the hospital where she got out, disappeared for around and hour and came out and said 'I wasn't actually pregnant'. She never showed however she was a slightly bigger girl and so everyone put it down to that.
It's a shame, as much as I despise this sort of behaviour it generally is a cry for help.