First you have to accept as you said that she is moving on. So that means her heart is closed to any more ways to really be a couple. It sounds like you have started to accept that. I fear that by helping her you are leaving the door open that says I want to be together so I will be around in case you change your mind. You are going to get more and more despondent the more you help. You have to protect you first before you help her. There comes a time when you can be too nice. You also have to consider that she may be asking for too much. She has to find other resources than you to help her at her house. She can't expect that she will move on and then call you when she needs help. At some point she is going to have a guy and want help and you are going to eventually feel resentful.
If this has been helpful press accept