Hi sayang! Don't worry too much, setiap baby punya timeline dia sendiri, so it's normal kalau dia belum rolling over yet at 4 months. Yang penting sekarang adalah during tummy time, check if she can lift her head and chest up nicely, and that her neck and shoulder muscles terasa kuat enough, kalau dia tengkurap dan boleh angkat dada, that's a good sign even if rolling belum happen. My friend's baby didn't roll until nearly 6 months and the paediatrician said it was perfectly fine, so jangan stress sangat! Tapi if you notice she seems very floppy, gets tired easily during tummy time, or her head keeps dropping to the side, worth bringing it up with your doctor or nurses just to put your mind at ease, they can do a proper check and give you specific exercises if needed. Mummy, you're doing great!