Excessive texting makes you common to her, just like her girlfriends who text minutia with her all day and all night.
You need to be a man who conveys he is too busy to text. She should envision you picking up the phone to text her as a necessary nuisance, an interruption from the important activity you're involved in. The LAST thing you want is for her to envision you lying on your back on your bed holding your phone and chatting away just like she and her friends are doing.
The moral of the story: Don't do friendly, lengthy chats via text. Use it to convey meetup information and as an occasional brief exchange (two or three exchanges MAX) in order to tease.
Text chats kill her interest because in so doing you're making yourself common. Always remember that you are above her and that a woman can only stay interested in a man who she perceives as above her.
You're too busy to text. It's a minor nuisance, a "concession" of a line or two because you're briefly acknowledging her in spite of your busy day or night. That's what you need to convey.
I have killed several women's interest in me by engaging in friendly chats via text, even when I knew better. Think of a text chat as an open faucet where her interest flows out of her the more you chat with her. Be friendly, be witty, but be BRIEF.