As sad as a miscarriage is, Dren sort of has a point (but he should have put it in a better way). At three months the foetus is technically not alive yet, and thus technically nothing died. This is one reason many people believe in abortion so long as it's before six months since it's believed the foetus has no mind yet.
Also, at 18 having a baby seems sort of.. I dunno... iffy. From what it sounds like (please correct me if I am wrong) your friend is alone with the baby. If this is so it's slightly unfair on the child to have a single parent with little life experience yet and probably not much income or a good job. I could be wrong though and please, don't take this offensively because really I do feel for you and your friend. It must suck to have the excitement of a baby even if (emphasis on the word if) it is accidentally, and then have it taken away from you. Send her my condolences.