Very Unique Txt-Game Situation!

I'm betting there's not a widely known rule or convention for this one:
So I think I've done a decent enough job DHVing and building Comfort since I can get this girl to laugh a good amount of the time and we carry great conversation when we're together. We recently hung out and there was the slightest of Kino Escalation up to brief hand holding and a big hug at the end of the night (wooooo big effing deal I know ). Upon parting, we made indefinite plans to have a casual dinner together and finish a movie, not necessarily on the same night. I think I've got a very good chance of her NOT flaking on me, so long as we solidify these plans decently.
A few days ago I texted her a question, she responded. I paced her response time by waiting the same amount of time as she did, and responded with a comment about an observation I made relevant to the (2-text) conversation. She has not responded for a few days.
HOWEVER (and here's where it gets unique) about an hour ago I saw on Facebook "Got new phone, lost my numbers. Text me please!!!" Now I have to consider not only how to deal with the fact that the convo got dropped, but also with the unique situation of her not having my number. It is no longer an option to wait for her to text me, since that is now impossible.
The question is, how long do I wait now to text her back, and what do I say?
Do I ask her to solidify these plans and pick a day, acting as though I didn't even see the status update on facebook?
Or do I text her just my name so she has my number, and see if she'll text me back about these plans?
Thanks for your help in advance. You guys always seem to make this stuff clearer for me

first off, since she doesnt know ur number anymore. text her causally and when she says who is this you can say something silly that will make her laugh like "oh nobody, just ur future ex husband" and then as far as solidfying your plans all you have to do is use future projection and possibly say a time frame like "oh hey im free in a week for two days, we should meet up and you can cook for me and ill treat you to a movie aka a dvd with dinner haha"