AITA for not deleting old Instagram comments

Me (24M) and my girlfriend (20F) have been together for 3 months. We have follow each other on Instagram since we met 4 months ago.

Today, she was going through my page and seen some comments from a picture I posted a while back, a girl I was friends with from high school commented she misses me under a post in a friendly manner. The post and the comment were made before me and my girlfriend got together.

My girl asked me to delete the comment.

AITA if I don’t?