Is it mandatory to post your partner on social media

I am a very reserved guy and I dont like sharing my life on social media. I like no drama and attention. I love staying low key. Few days ago my sister(not sibling but someone who I know from a long time) got mad at me saying I am a red flag coz I never post my gf on social media. She pressured me to post a pic of gf on social media. I had no option so I did post a pic of my gf. She said whenever u miss her u should post her to make her happy. I had completely different opinions but I didnt wanna argue with her so I didnt say anything. I havent uploaded photos since 2020. I just dont enjoy social media and I dont need validation. My gf understands me and she has no problem with me chosing not to post her. I want my relationship, family issues, career and everything to b private. But my sister thinks I am red flag. Whats is ur take on this?