Seamstresy or Seamstressy: How To spell?
The word Seamstresy is misspelled against Seamstressy, a noun meaning "The business of a seamstress."
Seamstressy has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings seamstre & y which should not be misspelled with single 'S'
Wrong Spelling:  seamstre-s-y  Correct Spelling:  seamstre-ss-y 
Explore spell check of Seamstressy to spell without errors.