My baby was around that weight at 1 month too, and my paediatrician told me that what matters most is whether they're gaining weight steadily, not just the number on the scale. 😊
If your baby was born at a lower birth weight, 3.6 kg at 29 days can be completely fine. As long as she's feeding well, having enough wet diapers, and seems alert and content, I wouldn't worry too much. Of course, it's always best to check with your baby's doctor at the next visit for reassurance.