Vicki,
I can't possibly say how sorry I am for the magnitude of your loss. My heart goes out to you and your girls.
I see that you are in the Chicago area like me. I have a friend and former colleague who, with her minister husband, is involved with Rainbows, a grief support group for children. There is a group at the First Presbyterian Church in Evanston, 847-864-1472 ext:243. If that is too far away from you, I bet they can give you resources closer to home.
My prayers are with you and your family.