Hmm, I'm in two minds on this one Jim. I know you feel it's unfair, but might you just want to leave it? Would that be a 180 for you? Just accept SIL is unhappy, not try and justify yourself and move forwards?
Often a little space and time will resolve things that a letter sent now may not.
If you do want to send the letter, I think it's okay - although, I would take out that last sentence in para 3 about selling the house..
You may want to 'sit' on this one for a week Jim & see how you feel then.
Also, what did happen to Gran's money (if you don't mind me asking?) Do W's family have a legitimate grievance?
T 13 M 7 Me 48 H 46 SS 15 BD 7.14 PA D final 5.16 (H filed)
We receive & we lose, and must try to achieve gratitude & embrace with whole hearts whatever of life that remains after the losses - Dubus