I think it's pretty normal for any person to occasionally miss how things were in their early 20s or at other times in their life. We tend to forget the minor annoyances and inconveniences that are always part of life -- and the early 20s are typically an exciting time, so much life to look forward to, so many possibilities, so much fun to be had all around.
Of course, too much reminiscing is unhealthy. Like most things in life, it's a question of finding the right balance, don't you think?
I have noticed that when she starts to look back in the past she realizes how good she had it at one point with me.
In that case, I would think she'll most likely think of your time together eventually. How could she not think of her time with someone she married? What would knowing that do for you? Are you hoping that she'll reach out when she starts thinking of you more often?