If you like her, why not just tell her that you like her? Then, you can text as much as you want to!
How often should you text a girl? By often I mean, should you text daily, or skip one or two days. Especially if you are want to date her.
If you text once and they don't reply ... That's it. Game over. They aren't interested in texting you.
Every day
Girls looooooove the attention. So do not be afraid to be active and text as much as you want. Wish her good morning and be the last who writes sweet dreams. You will notice if she is interested in you or not.