Pregnant while on Depo provera

[JOHN/BETTIE DEWISPELAERE]

My daughter, who happens to be in the US Army, had her first baby almost
two years ago.
Since then, she had been using Deep. She has had headaches and abdominal
pains almost
continually since then. About 4 months ago, the doctors said she was
pregnant. About a week later they told her she had had a tubal pregnancy
and then a miscarriage. Now they tell her again that she is pregnant, about
13 weeks.

My questions are these: Is Depo usually so unreliable? Is there any chance
she will carry this baby to term? What about birth defects? What about long
term effects to her?