I thank you all for your input. I do think that I might get a second (vet) opinion and maybe wait a little longer for her to mature more. I have no intentions of breeding her. I just worry about her maturity and anesthesia risks. Which unfortunately, cannot be predicted. But, I do at some point want to have her spayed to help prevent possible future complications.
So, that being said, please don't blame yourself for Millie. You did what you thought was right. I feel for you.
