Baby girl pretty much hates purees. Advice?

She was born 7 weeks early, and her dr told me to start purées at 4 months, but I felt like it was too early. So we waited til 6 months and it seemed to start out ok. We did all the basic flavors, 3 days in a row, before staring a new one. We’ve done some stage two now but the past few weeks it’s so hard to get her to eat them. She will take one bite and then close up shop and refuse to eat more. She will however, woof down 1-2 bowls of oatmeal cereal before bed. I’ve given her some mushed up avocado a few times and she seems to like it, but she gags on the smallest amount so I’m not sure if she’s ready for other solids? What do y’all think? Any advice for me?