Yeah it is a tough spot to be in. The best way to deal with it is to confront head on. It sounds like you may be alone in the confrontation which is just how it goes sometimes. Say everything that's on your mind to your sis. If she doesn't want to hear it then all you can really do is remove her from your life (at least for a little while). She may start to get it after awhile. The other thing to try is fam counseling but it already sounds like she won't have any of that which is why I default to the previous idea. You could wait until after Mother's day but make sure to write it all down so you know exactly what went wrong where and the cycle won't repeat (hopefully). In the end some people listen some don't at this point it may be protection of you and your daughter. Some things to consider at least