Attention Preemie Mamas

My LO was born 34+3 and is now coming up on 6 months old. She is healthy but still on the smaller side. I have noticed that compared to babies her age she is "behind" as far as milestones go. I know babies tend to do things on their own time, but in your experience have your LO's hit milestones based on their actual age, adjusted age, or just when they felt like it?