Based on your self-description and your string of fields within nursing, I don't think you should commit to anesthesia at this point. It appears you get bored or sidetracked within your field and move to another. This is fine and one of the great benefits of the nursing field. It doesn't seem anesthesia has been the center of your planning either, having 4 kids by 29. Not that it can't be done with kids, but I'm surprised you didn't get grad school done earlier, if you were that focused on anesthesia. If I were you, I would focus on finding an ICU where you're happy. Find a place with super sick patients in an area that you enjoy (neuro, trauma, CV, etc). It sounds like you just haven't found the right unit for you, but would enjoy critical care as a field. If you find all those challenges that you want and still desire anesthesia, see if you and your husband agree on taking the family through anesthesia school. But I don't think I'd do it just because you don't like NICU.
Good luck!