Having watched it myself and been confused i have come across
some answers:
The easy one is she is cushie's sister, and is offended by him
playing with her sister and further when he shares his first time
with her.
in the book i am told she is referred to often in his school
time, but only on the fringes.
she is an "ellen jamesian" and has cut off her tongue.
as seen in the movie (more in the book) ellen james herself
wants to forget the whole thing and wants people to stop the
mutilation and is thankful to garp for his book.
The other jamesians dont like this, nor his book, as it presents
a view of ellen james which differs from their belief of her.
so pooh is a screwed up girl, shunned by society and screwed up
more by the 1st group of people to accept her.
