There is no association between gall stones and abortions ...this needs to be looked into independently and treated as such by a gastroenterologist/surgeon. It is not clear from your letter whether this was the second or the third pregnancy (meaning have you lost the first two or the second and the third pregnancy). I am also not clear whether she has a normal baby at present or not.
At the outset I can tell you that most early abortions occur because of an abnormal conceptous and not because of any problem with the mother. Blaming the woman is unkind and medically incorrect. Doing too many tests and putting too many restrictions and precautions on the pregnant mother or giving unscientific treatments like bedrest and hormones will make it look as if the mother has an abnormality. The lady feels suspect and that is unfair. She will start blaming herself for somehow not taking enough precautions and in some way causing her own abortions.
22-24 per cent of all pregnancies are lost after diagnosis. If we take earlier abortions, almost 45 -55 % of all pregnancies are lost in early stages. 20-30% of all sperms and eggs are abnormal and as a result upto 50% conceptions are less than perfect. By natural selection all these pregnancies are aborted early. In all probability the reports will be all normal and it is only coincidental that she has lost two in a row. you do not need to worry too much and she needs a lot of emotional support at this stage and being too dejected or going on a witch-hunt for a cause will only make it more difficult for both of you. Please let some time pass and when you have recovered from the loss we can discuss it further. Meanwhile, if you want to know all causes you can read about recurrent abortions from the royal college of obstetrics and gynnaecologists site at www.rcog.org.uk.