Your question deals with 2 main issues
a) Can your friend's, soon to be, ex file bankruptcy and leave her with debts? Short Answer: Yes
b) Can your friend do anything to stop this from happening if it is a possibility? Short Answer: No
But there is hope. Just tell your friend to remember this: Bankruptcy and Divorce often lien at the opposite poles of the law. To see this difference in action, let's consider how these courts handle assets and liabilities.
In a divorce action courts are primarily concerned with preserving the unity of the couple or family. Judges have wide-ranging (often too wide-ranging) powers to ignore who owns what and simply take from one side to balance the other. This means a divorce court judge may require your friend's husband to give up property like the house so that his wife and children can live there, or require the husband to pay the couple's debts even if they were in the name of both husband and wife.
In a bankruptcy action the opposite is true - each party is responsible for their own assets and liabilities: there is no fuzziness when it comes to who must pay. If your friend and her husband incurred debts together like the mortgage on the home, credit cards, car payments, etc., then if one drops out due to bankruptcy the other gets stuck with the bill (so to speak). That's it. No special considerations for being a couple, no special treatment due to hardship or tough circumstances. But remember, this means that your friend can file too and leave her husband stuck with the obligations.
But here is your friend's trump card - obligations imposed by a divorce action (alimony, child support, property settlements) CANNOT BE DISCHARGED IN BANKRUPTCY. That means once your friend gets the divorce judge to rule in her favor as to what she must get from the husband, she is bulletproof (if he pays - if he doesn't he can go to jail, and most people respond to that).
I hope this information has been helpful. Feel free to contact our office with any questions or follow up.