New born pram positioning

Hi, my 5 week old has been in her pram at a 150 degree angle as I read somewhere that this was ok. She has problems lying flat because of reflux and is more comfortable in this position. However someone pointed out to me today that it could be damaging to her development not just on her spine but also her lungs. 

She does wheez a lot and now has what sounds like a cold although no runny nose. Have I hindered her lung development by using the 150 degree angle? I have been taking her out in it once a day for 2-3 hours. 

At night she mostly sleeps on her side if I can get her to settle in her crib or on me.

Would appreciate any advice or to hear similar experiences, thanks.