Sadie is cute but I don't particularly like it. It sounds less old than
Sally, but still too childish to be a full name. I like the look of
Sallie better than
Sally. As a general rule, I think -ie is cuter and less common (
Mollie,
Dollie,
Ollie, Tollie, etc).
Sarah is a good name, but its kind of boring. I would use
Sara if I had to pick any of them, because its short and to the point. I wouldn't use any nicknames for it because it can stand by itself, I suppose?
https://youtube.com/@MarioDrama632 or
https://youtube.com/@Objects_2763 :3