So did you propose already?
So like some, i think waiting would be wise. I feel that if you think your ready, give it just a bit longer. I say this because sometimes certain things in our life push us to certain feelings and you should really be sure its not a passing thing. You both may be ready for marriage now. If you are, more power to you. If there is any hint of doubt just wait.
If you do propose or already have, make sure to give plenty of time to be engaged.
My proposal:
I was out of town for 3 days leading up to our 4th anniversary of dating. Her car was in the shop at the time so i left my keys and a note for her with basic info. I sent her on a 3 day scavenger hunt planned around certain time/days to make sure it lasted the 3 days i was out. I sent her all around the city hitting significant spots for the both of us. School, work, family, firsts, dates all that stuff. She would pick up a different clue/riddle each spot. The last clue i called her playing only "our song" (from a phone number she didn't have) and immediately knew where to go.
I was waiting at the park where i asked her to be my girlfriend and asked her to be my wife.
She wanted something private so thats what i did. A friend will be proposing with family and close friends and yet another friend wants to propose VERY publicly. She loves attention so that will work for her/them.
So if you did propose how did you do it? If you haven't do you have plans or a basic idea?
Best of luck no matter what you do.