He would be willing to help out without question - not sure she would go though .
Hand on heart now it also would make me feel like a failure in that I can't cope .
I wouldn't look at it that way. Although I obviously have no idea what it is really like being a parent. I know at one point one of my friends moved in with us for a month because her Mum and her were at each other's throats all the time, it wasn't terribly healthy for either of them. Whilst it wasn't an easy decision for her Mum to make she decided that if she didn't do it she was going to ruin the relationship irrevocably.
As to whether she would go or not, don't give her the choice. She goes or she loses everything. Pocket money, laptop, tv, bedroom door. Alternatively can you not go elsewhere and her Dad move in if she is refusing to go anywhere or is that too icky?