In a train station

Today, I got some good news from Noura. She found out that she is pregnant with a baby boy :) I am so happy for her but at the same time it feels so weird. You see, for me, Noura - who although is a couple of months older than I am - has always been like a kid sister to me (I am serious so don't laugh :) ). I have always felt that she needs sisterly love, care, and attention (not the brat kid kind of attention, but the sweet kid kind of attention). So, seeing her becoming a mother is really weird for me because I still feels that deep down she is still an innocent child herself!
Today, I feel weird. I feel like I am in a train station. Almost all my friends have boarded the getting-married/having-children train, and I am still sipping my coffee in the station and watching them from the table I am sat at. Don't get me wrong, I love being in the station and do not intend on getting on any train anytime soon. But, sitting in the station watching everyone else getting on that train makes me feel a little left out (the number of non-marrieds & non-engaged friends is diminishing), as well as enforcing in me a feeling which my Middle Eastern background is very good at instilling in people: Will I, in the future, regret not having gotten on the train earlier?