I don't get Blondie's issues at all. In her dream, she confessed, her friend said she was dear to her, her best friend, and that wouldn't change. So, even according to her dream, there's no danger of ruining their friendship. And in real life, her friend has gone along with 90% of her inappropriate requests, and has been sending her sexy pictures. What is going on with her?
It's called "being too preoccupied by things running around in your head".
People tend to not see the full picture of what's going on when they're directly involved.
It's not uncommon for her to think "nah, that can't be right. She's just going along with me to be nice" or maybe something along the lines of "was she always like this? I'm a little too nervous around them to tell."
She's still stuck on that rejection in her dream so it'll be hard for her to separate that one possibility from how she views things in reality. To figure out things in unfamiliar territory in a more logical/analytical way isn't exactly what what you'd default to doing -- especially not when emotions are what's driving your actions.
You can't expect people to know what the best course of action is right off the bat. Especially not teenagers who are experiencing those things for the first time.