Your DD needs to understand that if she's a signatory to a mortgage, or a car loan for example, then she will remain responsible.
However, if there are joint bank accounts or joint savings, especially if there are overdraft facilities that he might now decide to take advantage of, she simply needs to write to the Bank putting them on notice that they are now officially separated and she will no longer be responsible (from the date of the letter) for any debts which might be incurred on that account by the other signatory, i.e. husband. She needs to have an account in her name only and to ask the Bank to place half the funds from the joint account into her new account. (Well, half the funds would be the 'civilised' way to do it!!) The Bank will probably then get him to open a new account in his sole name, but that's not your DD's concern! She's off the hook.
Make sure from that date that all and any accounts she has are in her sole name. Unless she has been involved as a guarantor for her Husband, there is no future liability on her.
He cannot 'run up' debts, unless they are in his sole name and he is then totally responsible and, again, she is not at risk.
Get her to see a Solicitor a.s.a.p., and take advantage of some free advice. This is normally advertised but most firms will not charge for a short first consultation, unless they take instructions and agree to carry out some work on your behalf.
This advice was given to one of our children who was seeking a divorce. It should hopefully settle your DD's concerns about what she can do initially to avoid being worried about how he may handle money now and where she's anxious that she might be liable or involved.
