Ok, so today isn't Valentines Day. But as I tell my wife, EVERY day here is Valentines Day (That's why I never buy her anything. You can guess how that goes over!)
But I purchased this early 1870s envelope recently (can't tell if the stamp is a 134 or a 145 or a 156. The target cancel is covering the pearl where the secret mark is, and I can't find any of my magnifying lenses).
It's got a nice frilly cover and is postmarked on February 14 in Franklin Mass.

Its a good size, so one would assume there would have been a nice big card inside for Miss Ada.
This is what I found...

...this delicate little embossed love card measures 2.5 inches top to bottom. No name. Whoever her suitor was, I hope he got her chocolates too!