For what it's worth my advice would be to find something cute to knit for her in a child's or young teen's pattern book. It isn't just a matter of knitting this dress you found in a smaller size. This pattern is designed for a woman's figure with the bust and hips sized for a woman. Knitting the entire dress smaller is not going to allow for the other design changes this dress would need to fit a child's figure.

I agree with Patty.

Annie

I kinda thought the same thing about the bust and hips and I explained to her that it wouldn't look the same on her because she hadn't gotten her womanly shape yet so I spent all day yesterday searching for a dress that she may find equally beautiful but I really didn't have a lot of luck. There were several cute little numbers on garnstudio.com but again I run into the same problem with having to resize the garment. Some designs looked simple enough that I may have been able to do something with it but I just don't know.
Does anyone know where to find a dress that just as pretty for a pre-teen?

Why don't you find a basic sweater top that she likes and just add a skirt to it?

Annie

the Standard Body Measurements/Sizing charts on the attached link may be useful to you regarding resizing anything. I don't really knit (at least not enough to make a dress) but look at some of these on the Knitting Pattern Central site and perhaps something in a small size could work - the children's clothing is probably too small but there are some dresses there also

Here is a link that might be useful: Standard Body Measurements/Sizing

Early June can be rather warm, depending on where you live. I would get her to pick a nice dress that is suitable for warm weather. When my DD got to that tween stage, I often shopped at stores that provide low priced and mostly teen choices where they cut corners so much in manufacturing that they tend to make the clothes a little smaller and so I could get a better fit for her.