If I were in your shoes, I think I'd want to be where I'd be taken care of. Sounds like living with your sister would ease a lot of stress and you could take care of yourself better than if you were trying to support yourself. The doctors said 20 hours for a reason....they know best. I would stick to the 20 hours since your sister is willing to help! I would only go against what the docs say if it's a desperate situation. Family is there for a reason too. If it were me, I'd accept the help and take it easy!