Hi there Hollie,
There is no real way of knowing how busy it will be at this time (because there are basically 2 things going on at once in March....like you mentioned Kids on March break and Easter time!). One can only assume, in March more children will be there
and it being during a holiday time, that more than likely it may lighten up for you by April 9th, when you will be arriving (and the weather should be perfect!). Congratulations, by the way, on your upcoming trip, it is always so exciting when you get to dream about your trip and the things you will be doing, once there and ahead of time!!!
Follow this
link in order to see the Extra Hours available during your scheduled trip! This one is for Magic Kingdom, but if you want the hours for the other parks all you have to do is
go to the main page, then click on the park you prefer and click the Extra Hours you are looking for (this will give you your answer for the morning and the evening added times to spend enjoying the parks!!!!!). I hope this helps you.
Enjoy your stay!
Brigitta