My first thought is that Cecily was medieval princess
daughter of William of Normandy and sister-in-law to Henry VII
when I think of Cecily I think of medieval times, of medieval tapestries and medieval English field with sunshine on it
second thing I think of is Saint Cecilia, the patron of musicians, but not because I'm religious, but because it's so rare name where I'm from
I also think of meaning "blind" I think of Saint Lucia (common Saint where I'm from) holding the plater with her eyes - this was iconographic when I was a kid, my gradma had some portrait in such manner.
another thing I think of is that ceci is chickpea in Italy... they got calling chickpea chocolate cookies Cecile.
What do you think of when you think of Cecily or Cecilia?