In fairness to creditors, had you received the maintenance you were entitled to from your ex husband, you may not have had to enter an IVA. Therefore they are entitled to the monies as they subsidised your living expenses as the children grew up.
If however, you are receiving legal aid, it is possible that this may be withdrawn if the beneficiary of the award is your creditors and not yourself. It may be worth speaking to your solicitor and possibly calling a variation because if the legal aid ceases it may be impossible to recover the money. You could explain this to creditors and offer to voluntarily split any award which may be suitable to all concerned.