i too had a kidney stone while i was pregnant.. i got prescribed vicodin but only took a half of one each day.... and it helped take the edge off of the pain ..
She needs to speak with her doctor regarding this issue. No one on the Internet should be answering this question as there are many factors only her doctor is aware of at hand.
I passed a 7-mm stone earlier this year...she has my sympathies! Interestingly enough, I found that using pyridium helped more than narcotics when it came to the pain. Something worth mentioning to the doctor.
we are not dr's here.. there is a risk with any med.. I had a kidney stone at about 14w.. thought I was going to die but I passed it with no meds.. it will be a decision she will have to make and live with.. good luck