Hi,
   I understand your concern .
   In 
pregnancy pregnancy hormones level rises in body. this causes slow bowel movements, as a result food lies in intestines for a long time,the water content of the feces is absorbed to make them dry . This leads to 
constipation.
    To manage your daughter's case-
    - give food with good fiber content ( Plenty of vegetables, salads,fruits with skins(whenever possible), unprocessed grains.
    - Let her drink 10-12 glasses of water in 24 hours.
    - A glass of hot milk with 1 spoon of clear butter at bed time helps in softening stools.
    - Alternatively she can have mild purgatives like 
cremaffin /  
Lactulose suspension (
Duphalac) daily in the beginning.Glycerine suppository helps in very hard stools.
  * At present she has taken a double dose of stool softner,& getting cramps . ...Let her take rest, plenty of water,
liquid diet.You can give half tab. of Baralgan if pain is too much. 
     -let her have light diet for a couple of days & then start with the advised diet.
    Thanks.