Do i need I need a gift for an engagement party?

my friend is having an engagement party next month. Her fiance's parents planned it. I'm just not sure if I should bring a gift? Some say yes and others no (because you gift at the shower and wedding) and others say it's optional. I would like to give her a small gift...nothing expensive since I'm going to spend a lot for the actual wedding gift and shower. I was thinking about maybe getting a personalized picture frame with their names on it? maybe putting a picture of the two of them in it with a nice card?