The saucer has a embossed pink heart for the indented pink heart in the bottom of the cup.
I found it at the same second hand store. It might have been there all along but I just didn't see it when I bought the cup.
I also found out that this cup and saucer set was made by Starbucks in 1995 (marked on the bottom of the saucer). Interesting the cup was not marked.
And yay I have a complete cute set of pink heart cup and saucer!