I say take it slow. It's never a good idea to date someone you met online without first knowing more about them. Give her some space. There is no need to text every single day.
We've been fb msg for 4 days now. The 4th morning she text me Good Morning. The last text I sent her was, good night. She replied Good Night. Since then, we haven't said anything. I think she likes me tho. Should I text her tomorrow?
It's a bad idea to date someone online who you don't know. Anyway, it doesn't matter really; if you want to text her, text her. If you don't want to, don't.