To my mind there are two scenarios to consider.
One , she is not a particularly as close a 'dear friend' as you think.
Two, is she suffering bereavement and was hoping to extract a hearty conversation with somebody she values as a 'dear friend'? Did she mean something other than coming over as being cross with you, it could be she is sitting at home beating herself up over how she spoke to you!
Just because her MIL was aged, died 18 months ago and she had a tenuous relationship she could still be suffering from bereavement, guilt issues. Maybe you could try to contact her saying how hurt you were over this matter but as you respect your friendship you are wondering if she is OK or needs a chat. If she blows your head off again then I would say you need to reassess the strength of your friendship.
Good luck, I fully understand where you are coming from but taking things at face value can sometime cause us to be hurt for little to no good reason. I would certainly find out rather than let things fester though,.
Moths I had never seen before have appeared in my garden


