I have read up about Si and Ni. I have definitely pinpointed Fe and Ti as being two of my functions.
My immediate family is mostly made up of SJs. My younger sister is an INFP. She's pretty sure I use Ni and Se.
But...I feel like I can somewhat relate to Si too! Both Ni and Si! Why is that?! Could it be because of my Fe tendency to be chameleon-like and adhere to the values of the people around me...thus feeling kind of Si-ish occasionally depending on who I'm around? If that makes sense.

I do love history and learning about the past, and I wish we were somewhat still kinda like how people were back then. But I also enjoy current trends. When it comes to history, I like to look at it from a mostly fictional point of view. For example, I write historical fiction. Instead of focusing my attention entirely on actual events that took place in history, I like to learn about the daily lives of people and families back then, what they looked like, etc. and make my own creations out of that.
If anyone could help me I would appreciate it.
My sister has definitely decided she's an INFP. I wish I was as certain about my type as she is of hers.