Rebecca needed surgery as she had free air immediately. HOWEVER: she was 37 weeks and a good size, about 2.8 kg. Her NEC also was probably due to feedings. It's thought that feedings colonize the intestine with its first "foreign" bacteria and some babies have more of a reaction to it than others. My daughter, as it turned out, was highly allergic to milk protein and I was too sick for her to receive breast milk right away. She also had critically low oxygen levels at birth, which impaired the blood flow to her intestine.
NEC is scary, no question. Is your baby in a place where she could have immediate surgery if it is needed? Obviously, I hope it's just a matter of antibiotics and time. It's a good sign that she is still only on CPAP and there is no free air. I will keep Kayleigh in my thoughts.
Rebecca had a colectomy when she was two days old, and was in the NICU for a total of 8 long weeks (as well as contracting meningitis). She is a healthy normal teenager now, though, and I will hope for the same outcome, preferably MINUS the major surgery, for your little one!