This usually happened to us a few times a season when I ran in high school. We'd have a dual meet Tuesday or Wednesday, then an invite Friday or Saturday. I was a two-miler as well, and to me your plan of a "paced" mile is sound. Have her run her two-mile pace for 1000-1200 meters, then let her go. It'll give her confidence to finish fast on Saturday, and it shouldn't tire her out too much. I like the long cooldown as well. Have her go a little shorter than usual Thursday for recovery, then normal premeet Friday, and she'll be good to go.
If anything, I'd probably race her in an 800 or 4x400 as well, just for a bit of extra work. She doesn't have to try and run an 800 or 400 PR, just race the other athletes; get the feel of having others close by when running a quick pace. If she's as good as you say, she might not have that experience. And while I know the invite is a big deal, remember that the important meets are at the end of the year (and won't be hindered by dual meets!), so if she's a little flat for the invite it's not a big issue.