We went through similar thing with our Grandchildren & our dog Amber although its different for us because they don't live with us , they go home at the end of the day. When they were crawling ! Even though Amber was behind a stair gate she was very "on edge" & when they started walking Amber didn't get any better, we got to the stage where we had to put the grandchildren first but we tried everything to solve the situation.we decided to ease Amber's anxiety by keeping her out of sight of the children as much as we could so she relaxed more when I look after them, the children are now three years old & Amber will still bark at them but not so alarmingly , she now accepts them coming up the the stair gate in the kitchen & they give her treats when I am watching over them, when my husband is in the room with us all Amber is allowed to come in & lay down next to him where she will just lay & watch them, I still don't trust her fully but now that Amber is three & a half she definitely isn't so on edge with the children, I do feel for you because of similar experience s , for us I am so pleased we still have Amber, but as I said its easier for us as the children don't actually live here full time , I wish you well x