This was her at 3 months and like a week after she mastered it. Also a lot of floor time helped
If you have Instagram here’s a video with some tips https://www.instagram.com/reel/DCxNyoAucVI/?igsh=dXhnNnhpNWV0Yjg4
I started by holding her hands and feet together (kinda like a hog tie position) and rolling her side to side like a game with a song. Then added more side play and guided rolling
I used toys to help her