Keeping in mind that this is not Shakespeare, Chekov, or Ibsen here... it's a great movie! Every teenage girl should see this movie -- yes, it is a bit "old" by today's standards, but the plot is still great.
When Katie blooms into this glamorous, teen vixen overnight (with the help of her dad's girlfriend) her overprotective father is baffled and disapproving. When she first came walking down the staircase, backlit in that white eyelet dress and Frankie Avalon comes on in the background... I wanted to be that girl! Any twelve year old can appreciate this movie ;)
So... if you like lighthearted movies, this is a fun coming of age story that's worth a viewing.