Feeling exausted

My hubby had to go spend the night with his mom at the hospital last night. Normally it wouldn't be that big of a deal but our dog has separation anxiety. If ether one of us has a long day and we are gone from the house for more then 8 hours she freaks out. Neither one of us has been away over night so she freaked out all night thinking he was coming back. I understand why she has the anxiety because before I was in the picture is ex wife left her behind when she left him when he was gone for the week for work. It took a long time for our dog to get truly attached to me because of his ex wife. So my question is, does anyone know what we might be able to do to help her with it?