I think you are forgetting the fact that this girl went out of her way to ask me out, despite flaking later. She continued to flirt, made an opening for me to ask her out, turned me down. She then took it upon herself to go out of her way to initiate conversations with me and approach me lol.
This isn't some she smiled at me once scenario and I'm not the one causing any of this.
None of those details are relevant. There are only two relevant behaviors:
1. she actually goes on a date with you
2. is she physically intimate with you, skin to skin? Lips to lips. Genitals to genitals. Lips to genitals.
If the answer is 'no' to either, she is not interested. There are only 4 possibilities here:
Top category 1: she has sex with you and you don't need to take her out on a date first
Top category 2: she will have sex with you but only after dating you at least once
Low category: she will date you but won't have sex with you
Lowest category: she won't go out with you and she won't have sex with you
(your category).