It is an "s" though. The "s" was different, depending if it was used in the middle of a word or as last letter. It is the same in the old German Sütterlin handwriting, therefore I know this. Because of the loops above and below the line that letter in German is called "Peitschen-S" (= whip-S), because the letter resembles a whip. As opposite to the round "s" which was used at the end of a word and therefore called "Endungs-S" (= endings-S)
Edit: and if you compare the first letter in the word "Miss" to the first letter in the word "Will" in the next line, you will see the difference. So it is "Miss". The miss was fortunate to (hopefully) get such a nice love letter ...