Dwood......excellent stones on the "Brat" comment!! You are showing some very nice signs of innate PUA game. BUT...like a boxer in a ring, you HAVE use combinations. The fact that she texted you IMMEDIATELY was good... but you let her off the hook (and de-valued yourself) by saying you were flirting....why state the obvious? Of course you are flirting!
Here is what I would have followed up with....
Her: (instantly) How am I a brat?
You: C'mon...you know how you are a brat!
Her: No I DON"T!!! (I am guessing it would be something along these lines)
You: Look, admitting it is the first step in fixing this...
and take it from there....basically, you scored a perfect NEG!!! and by keeping on that theme without explaining yourself, you keep her off balance, guessing, AND INTERESTED!!