re: Power of Attorney

If she has filed for and been granted legal separation, I would assume that she has an attorney. I would expect a good attorney to request she revoke her power of attorney and expect to receive the same from her former spouse.
Her bank account should be able to be signed onto by her parents simply by going to the bank and signing the paperwork with her present. Something to consider would be whether the assets in her checking and savings will be actually awarded to her in full by the court at final declaration, if not, she could be liable to pay back the portion that was granted to her former spouse.