I would definitely say take writing classes, because those will challenge you to improve your writing style. You can also listen to podcasts or read workbooks, which all have different advices on how to do writing and how to improve your craft.
Look at other examples of essays on the internet to get an idea of how a good essay should flow. Plan out your essay quickly before writing. Make an outline...
No, it's not necessary. You can format your text any way you like. Just make sure to format all items of a category the same way. If you use quotes,...
Think about the types of books she reads. Are they younger picture books or 300 page novels? Something more mature with better sentences and stronger pieces may help her learn...
If you would like to write long stories instead, go for it. You could also just write some scenes (dialogues, battles, descriptions, etc) for a long story. Skills will come...
