Entrepreneur Riddhima Kapoor Sahni, who is the sister of actor Ranbir Kapoor, says her daughter Samara being active on Instagram often makes her watch out for her, as the teenage is vulnerable to vicious comments of trolls online. Riddhima said she has asked her daughter that if she wants to be on Instagram, she has to make her account private but the teenager refuses to do so as she wants to get more “followers”. “At times it worries me, because she is (active) a lot on social media, she posts…