Honestly, what you're describing sounds like it could be a mix of two things, the normal noisy sleep that babies this age go through (they cycle through very light sleep stages and can grunt, kick, and even cry out briefly without being truly awake), but the choking or coughing sound one hour after feeds is the part I would not just wait out. That timing pattern, combined with the escalating distress, could point to some reflux discomfort, where the milk comes back up when she lies down and causes that gagging or coughing reaction. My neighbour brought her baby to a PD at KKH when she noticed the exact same post-feed coughing sounds at night, and the doctor picked up silent reflux quite quickly, something she would never have guessed on her own. To be candid with you, I tried elevating my own baby's head slightly and it helped a little, but it was not a complete fix and I still needed the PD's input to get things properly sorted. Since yours is consistently escalating rather than settling on her own, it is really worth getting a doctor to assess her rather than assuming it will pass.