I would just do one leisurely day ..
If you want to see all the shows, you'd probably struggle to get it all done in one day (just due to the timing of the shows)
If a few shows aren't interesting to you .. then .. sadly .. not much there anymore now that they've removed all the "movie magic" attractions.
I've always considered it a "boys" park, though they have tried to draw the girls there with the Frozen Summer Fun stuff. For girls that age .. they may be too small (or find it too scary) to go on the two big attractions there (Rock N Roller coaster and Tower of Terror).
I would definitely consider going to one of the themed restaurants there for one of your meals. Those are fun.
I am going there in August with my 3yo son and his two (girl) cousins (2 and 4) .. I have no doubt he'll enjoy some of the stuff there (even though he won't be able to go on a lot of the rides due to height or being too scary), I just wonder if the girls will be interested in the stunt shows.
As I always do with DHS .. if you are done for the day and don't plan to see the night shows .. take the nice boat ride over to Epcot. One of the best ways to park hop if you have the time for a long boat ride.
