First, ensure that the benefits are properly reported. Social Security is taxable to the person who has the legal right to receive them. Survivor's benefits paid to you (the widow's benefit) are taken into account on your return to the extent the benefits are taxable.
However, the survivor's benefits paid to your kids is taken into account on their returns, if their benefits are taxable. Most kids don't have enough other income to even be required to file a return, let alone have enough for the benefits to be taxable.
SSA should issue Forms 1099-SSA to your kids for the survivor's benefits they get. Those amounts do not go on your return--as indicated above, they would go on your kid's returns. You only take into account any payments you received for yourself. SSA should issue you a Form 1099-SSA for the benefits paid you. That's the amount that you deal with when preparing your tax return.
See IRS publication 915 for the details of how SSA benefits are taxed.
If you didn't get this right in past years and included your kid's benefits on your return, you may be entitled to a refund. To get the refund, however, you'd generally need to amend the return within 3 years from the due date of the return. This is done on Form 1040X.
Assuming that you've got the amounts right, then the next thing is to figure what the effect of the Form 8379 would be. Compare that to what you'd get back if you and your husband filed separate returns. If filing separate returns will give you the better result, then that's the way you ought to go. You have that choice.
You can get forms and publications at most IRS offices, have them mailed to you by calling the IRS toll free at 800-829-3676 (800-TAX-FORM), or download them from the IRS at:
http://www.irs.gov/formspubs/index.html