Catfan---good to hear from you again! I agree with Steve. Live YOUR life and make yourself happy and whole. Then, she can decide if she can do the work to catch up - don't "what if" yourself about where she may end up. The whole, One day at a time thing.
Your daily devotionals are asking you to be a good family patriarch and provider - you are doing that by not entertaining the MLC rollercoaster. You are even loving and respecting X as a person, leaving her to make her own choices and steer her own growth. God is giving you a pat on the back. Just remain your happy, past-the-anger self.