I only felt it challenging in the beginning because I wasn't sure how to play a mom. But now, it's a comfort zone which also comes with playing a role for 9 months now.
I don't know what Sir Andrew Webber was on when he wrote that score! LOL It goes from the bottom of any female range to the highest belt one could imagine all in a couple of measures. And Evita is only off stage like 15 minutes throughout the show.
In my contract, I was slated to do it only five times a week and that was grueling. I had NO life on the road. I stayed in my hotel room most days not talking to anyone until the show. But again, it's hard in the beginning, then your body gets used to the material and it gets easier as long as you have good vocal technique.