Her mom is okay with it, which surprises the girl.
The first one is correct. "It is like" the best decision you can ever make.
Saying it that way, is the same as saying that it would be the best decision that you can ever make, but adding more to it. Almost as if soeaking to someone who is overdramatic, and constantly say the word like.
I hope this helps
It's mostly written in 1st person if I remember correctly.
