What to do when your bestie makes rude comments about your SO

I started dating this guy recently, it’s very fresh and he’s yet to meet all my friends. He posted a photo of us on social media and I sent it to my friend in awe of how sweet this new flame was being. She made insensitive comments about his appearance and laughed at his grammar (he’s severely dyslexic). I didn’t react or respond at the time. But my frustration is brewing over it. What do?