so basically I just want to know for number #1 stated in this video:

She doesn't text back? Find out why here, and what you can do about it - YouTube

which is

1. Too much anticipation / nervousness: if a girl really likes you, she might be too shy to reply to your correspondence. She might end up putting a great deal of pressure on herself to do well with you -- or be too jittery to type out a reply or answer your call. She may really, really want to talk to you, but never end up doing so.