Can you help them without changing them?
I had to think about the way this was phrased for a bit. Yes you can help people without changing them -
Help can come in the form of being supportive, encouraging change, listening, advocating for professional treatment, having patience, taking care of your children if she is not capable at any point, taking care of yourself and your emotions, educating yourself on substance abuse and treatment options. There are lots of ways family can help.. and probably if you were to seek support from a psychologist, someone who even specialized in addiction medicine there would be suggestions offered to you based on your own individual situation.
We cant Change other people because that is an Inside Job. Think about it, can anyone change you? People can offer me suggestions, support, encouragement, even share their opinions, and suggest I do what they did. But only I can decide I need to change, and then follow through with what I think is necessary to make it happen.
This may not even be what you were asking, but I did ponder the question and for that I thank you.