One has to wonder just how badly LW handled things if this is the better version!

And yet, theoretically this one would be so easy to solve. Charly still speaks to her mother, which suggests that Charly is a person willing to extend considerable goodwill! Send her a sincere letter of apology that admits to the more recent failures of understanding, make a positive suggestion they come and visit and stay in your house in the same room (and if you follow up with a phone, offer a hotel room if they aren't comfortable). Take it from there! It's not hard! And yet LW makes it so hard.