Good morning - I'm Dr. Sara. I apologize for the delay in our response but I think that the Experts may be hesitant to tackle your question because breathing issues can be difficult to address without a physical examination. Do you think that there's any way you could get a video of one of these episodes? That would be very helpful for us to see.
Because breathing issues can be an emergency, I have to suggest firstly that you have her examined in person by a veterinarian. If she seems as though she is not in distress and she's eating and drinking OK and her gums are nice and pink, it's likely OK to monitor her and try to get us some video.
I'm going to include some videos that show my top two suspicions when my clients tell me their pet is having odd breathing. First is a reverse sneeze, which is benign and usually requires no treatment:
The second is a video of a dog with tracheal collapse, which can be life threatening if not managed appropriately:
As you can see, the differences are kind of subtle, so I would suggest having Harley examined as soon as you can.
Please let me know if you get any video :)