Ariana Grande has an pretty voice while singing and sometimes they have to adjust some notes sometimes but her cat voice is 100% real she just make her words really long or weird sometimes to make the weird affects so there's your answer
Yes, it is her real voice. She just tries to soften it up for the show, to make it suit the character more. For the non-kids shows and other programs, she just uses her normal voice the way it sounds. Hope it helped!
`Well, I kinda want to say...yes. Her voice isn't really that high pitched all of the time. She talks regularly when she's not in character. Ah! I know! If you go on Youtube and watch some of her bloopers, her voice changes when she's not being Cat. :) But I am sure that her "Cat" voice is somewhat a part of her when she talks normally. Heehee~ Hope that helped. =P