"Like floury fingers after baking." A very calm/relatable simile. It reminds me of baking with my mother.

"I stood immobile in the hoarfrost--I had no right to cry." Oh! I love the anguish, the bitterness enwrapped in this line--it's amazing! I like the harsh tone the word 'hoarfrost' creates--it definitely adds to the speaker's grief.

"Old, hawthorn heart." WOW! That's so sad...

P.S. Many blessings in the memory of Sam.