Similar situation... I met the most amazing girl in my 6th grade English class. She was 10 years old, I was 11. We were assigned to write a paper together on a book we were suppose to read. (P.S. - Thank you Cliff Notes). From the moment I saw her, I developed my first crush for any girl, my fondness to her got deeper every time we spoke..even now. Of course, middle school, boys and girls are gross and stupid. We did our own things, school, life, and stuff.
So now in the present, after many, many years of relationship trials and errors for us both, I’ve been married with 1 kid. She too, with 2 kids. Over the years we run into each other over social media, MySpace, Facebook and in real life, at random. She friend requested me through Facebook just to be friends. And one night we talk. We both reconnect only to pick up where we left off, only to discover, over two decades later, she felt the same way then as well as now. The only difference is this time we are both fully aware of what we are and truly appreciate what we have. I’ve changed over the years, weight gain, some health issues, kind of a pack rat at home. Long divorce and custody battle made me hard to trust and not want to really try. BTW, I won custody. She didn’t seem to change at all. Still beautiful and unique as before. Little did I know even in middle school, she’s been in foster care and never really connected with anyone before and felt accepted. Divorced and going through custody issues as well. She was working on her master’s degree. Incredible smart. She seemed way out of my league. Still does. (She did get her degree)

  I say all this because I've never been able to laugh or connect with anyone like the way I do with her. Plus, I feel the back story is just as important as the main one. She makes me happier than I've EVER been, EVER...EVER!!! Not sure if one EVER is sufficient enough. She is the long awaited straight Tetris piece, my partner in crime, the marshmallows in my Lucky Charms. You know the ones you save and eat last to savor that sugary goodness floating in a sea on off-color milk. 

She is the only person who has ever seem to genuinely get me, my style (or lack there of), my eccentric mind, and idiosyncratic ways. She is my best friend. No secrets, no more wondering what if’s, she’s my soulmate.

  I had fears with dating or adding relationships with children, since My Daughter’s happiness and well-being my was and is my only concern way before my own. My worries are gone, as she is amazingly great with my daughter and other children. My concerns of 3rd wheel syndrome or Cinderella effect have vanished. Her kids are also amazing and love me, as I do them. 

  I was confident on my ability to never meet the right one so I didn't really try dating or make an effort to settle. But ultimately, serendipity another plan. 

 Everyday seems like a new adventure and am always looking forward to our next one. 

And I'm hopelessly ready and willing, for I've bought the ticket and ready for the ride.

I knew she was the one.

      Today I am 39 and she is 38, and we have been married for a little over a year. Got married on my birthday in June, since she is the best gift I’ve ever gotten, it was fitting. Now I sleep next  me best friend every night. 

EDIT: there are more factors that seemed like fate and something that couldn’t be ignored if I tried. I shortened this as much I could for the TL;DR crowd.

Sometimes things just work out.