I have two daughters: one is five and one is eleven, and she was at Disney when she was five.
Both girls love HS.
My younger one rode Tower of Terror when she was three and loved it. We ride it every time- often multiple times.
For a five year old, there are some great shows. Little Mermaid, Beauty and the Beast, and Frozen are all very good shows and wonderful for a little girl of that age.
My older daughter always wants to see Indiana Jones, and they both love Star Tours.
There are characters at HS that you can’t meet at other parks, also- like Olaf, Doc McStuffins, and Sophia the First. There won’t be many more years she will want to meet those characters since they are for younger kids (with the possible exception of Olaf, whom we all love).
Sci Fi is my older daughter’s favorite restaurant on property. We always make and ADR there.
My kids also love Fantasmic. It is such a beautiful show.
Neither of my girls are big Toy Story fans, but they like the ride. They like to score points and play the games.
And Muppets, while not a priority, is cute if you just want a short line and a seated break.
No way would I skip HS with a five year old girl.
If I couldn’t add an extra day to go there, I’d do two at MK and one at HS.