hi yes i had a dry socket a few years ago, the pain normally starts a few days after the tooth was taken out and it really is terrible pain, apparently what happens is the blood clot comes out from where the tooth was removed.
I was told at the time that if you rinse your mouth and spit (sorry) then it's the sucking motion which loosens the clot, i was also sucking through a straw while my mouth was still numb and thats something else which loosens it. I had two weeks of anti biotics and strong pain killers it really is agony, as for the bit that has been left in it's hard to say my son had a small piece left in after abstraction and it worked it's way out within a few weeks.
She really needs to see a dentist asap.
Hope she gets sorted out she has my sympathy.