I think it's a hard one to respond to bc only you know what you want. Personally I would 100% roll the dice again as I believe for *me* that you only regret the babies you don't have not the ones you do. But then there was a thread not long ago where a member disputed that saying her mother regretted 2 of her 4 kids. Will you cope if it doesn't come naturally? Only you know that. I suspect that's why there hasn't been many replies - bc the topic is so individual and personal.
My only advice is to think in the future 10 years. It's just you, your DH and DD. How do you feel about that? Does it bring happy/neutral feelings or does it make you feel sad or think someone is missing? That's now I felt about conceiving my 3rd, like someone was missing from the family.