It's personal preference. Some people find social media natural extensions of their personality and some find it tedious. It's okay if she is not very active on it. She is a TV actor so her work on TV matters most.
Plus, I don't think being or not being on social media is indicative of maturity. It's not that all social media users are immature and those who stay away are mature. Look at Ranbir Kapoor and Kareena Kapoor. They are officially not on social media but are known to be gossip girls who even have secret accounts to keep track of their colleagues. 😆