Is it okay for me to be in love with my childhood friend?
What can you say about her?
It's very unique, she doesn't remember that we have met before in kindergarten...
That's great you can have such a long lasting love, but if she doesn't remember then it may have been fabricated. Memories that far behind are too fuzzy that you might have just made it up, so you just need to forget about that and move on to your future.
She is going to be the head of my next project.
I think it would be best to develop a relationship with her from scratch. Don't bring up the past kindergarten story and just let it start from where you are now. You can get to know her again over your school project and see if she likes you back.