I don't have any additional advice to offer, certainly nothing different or better than you have received . I did want to say, as a mom, how I feel for you dealing with all that is on your plate right now. It must be extremely stressful. I wonder if actually leasing a horse right now is really the best thing for you, and moving even further, into OWNING her may really just be adding so much more to your already heavy load. I am guessing that you do this to help your daughter, or to help yourself (as fun for a mom who needs an outlet). But, wouldn't it be easier to just stick with taking weekly lessons on a lesson horse? That way, you would not be responsible for so much, and you'd have this once a week thing that you both look forward to.
I dunno, it just sounds like you are overloaded, and your emotional state will very much color your interaction with an animal as sensitive to emotion as a horse is.
It's something to consider.