Context: Social Circle gamed, built attraction and qualified her.

Called her and played good phone game , built some comfort and made her laugh a couple times, and she agreed to go out to dinner [which I later found out her mother/family was standing next to her when she was talking to me and agreed(thats good?). Today I called back and started with some callback humor, expecting it to be easy, meet you here and at this time. She was still with her family and would not make it back until late. And here I did this but I said it very confidently and matter of factly, reschedule tomorrow?[if she said no I was going to block off comm for long while and next in the time being] but she said, sure! and then I said again matter of factly, "alright see you tomorrow then." and she was like 'oh, ok cya' and gave kinda single laugh. So I kicked myself for forgetting to give her the reason I had to go[usually it comes naturally but I totally blanked] or for not chatting for a extra min or two after rescheduling. I've heard it said that its always good to chat for a little bit after arranging a meet and giving a good reason to leave first. So my question is did I mess up?, or can it be seen as good since I did it with an alpha state , and both times she seemed enthusiastic about meeting up.

TL;DR: she flaked but agreed to reschedule tomorrow, I said alright and ended conversation immediately after instead of chatting a bit more, but did it in an alpha state.