Texting intervals, usual or not?

DrPain
Ok so there's this girl I know whenever we text or email each other it seems when we do this there is the same time interval between each text/email. So for example she texts me at 9:00, I would text her back at 9:10 then she would text back at 9:20 because I took 10 minutes to respond. Then I respond at 9:22 and she texts back at 9:24, 2 minutes. Or she emails me and I don't get back to her for 3 days, she will do the same and won't write back for 3 days. Is that unusual?
Texting intervals, usual or not?
1 Opinion