date there future spouses a significant amount of time >8-10 months before they think of getting engaged and married as well. The future suitor of my daughter will understand implicitly how serious I am about said timeline.
Perhaps my opinion will change over the years, but my wife and my transition into married life was far easier and simpler than several friends on both sides that dated and married all within a >6 month time frame.
Personal preference here and no comment on your dating/marriage time frame.