I'd recommend a Sotar 14X23 Legend or ST classic, a Maravia 14X24, or an Aire Ocelot. Looking at the Aire website, it appears they have dropped the Ocelot from their line, but there are always used ones to be had. The Sotar Legend will have a bit more rocker than the Sotar ST Classic. My older Maravia 14X22 had a straight top line and very little rocker, but my 14X24 was after they did a design change and added a little rocker to their cats.
A 14X23-24 will serve your daughter very well and I doubt she'll outgrow it. It's a really nice size cat to have in your fleet for multi-day and day trips. You might find yourself fighting her for it
Frame width is a personal preference thing and can be influenced by the cooler and dry box you decide on. I always ran with a narrower frame with 34 inches between the tubes. I liked being able to easily reach my oar locks in an emergency oar situation. that frame coupled with counterbalanced 9.5 foot oars made a very comfortable set-up for me. As a reference, I'm 5'5" with average wingspan. A 34 inch frame width does present some problems with dry box & cooler size though. 36-40 inches is a more standard size.
Whatever you do.....pick a cat with a rocking' fun color for her
My last cat was a beautiful teal color and the person who bought it got it for his wife as a Christmas gift. She wanted teal or purple.
Not too many dads get their kid a cataraft as a Christmas present. Big thumbs up to you!