Patience, trust, comfort, support, kindness and the strength to bear all things.
As for love, when your 25th approaches and you have both seen many of life's hardships as well as the joys that life has to offer TOGETHER and you STILL feel the desire to reach for her hand as you walk somewhere together... I will ask you what that is. In my estimation THIS IS TRUE LOVE.
ANd luck... well luck has NOTHING to do with a solid relationship.
What a wonderfully romantic proposal; simple yet obviously well thought out. Don't forget to do these things for her when you don't know how the mortgage will be paid or after her body has changed with the passage of time and the ravages of childbirth and the baby just WON'T STOP CRYING, etc and so on...
A solid relationship is like a garden that must be tended to with care just a little bit each day. If it is not neglected you will both reap the rewards and simples pleasures for the rest of your natural lives... and perhaps beyond.