She's confused, sweetie... and so are you.
Give her time and space and she will remember that you are the one she can depend on.
In a way, it is good that she trusts you enough to let her hurt out... even though it is horrible for you. Because it would damage her a lot more to keep it all bottled up.
Thistime of year must be very hard for both of you... and some of that is bound to come out.
Just keep remembering that her heavenly Father has hold of her, and He will bring her through it.
And - you are doing a wonderful job, sis. The fact that it is such a big issue when you fight is awesome... because for so many mothers and daughters that is the norm!
God is in control, sis, He has both of you in His arms, and He will bring you through it all.
God bless you very much.