Don't text her until she replies your original text. In the meanwhile go find something else to occupy that planned timeslot that is a not so bad alternative but can be pushed aside once she texts you back (eg. another date, go get some work done, catch up on some episodes)
Most importantly, don't get your hopes up about the date. Try to get excited for your alternative too so that if she really doesn't reply/cant make it, you wouldn't feel like your evening is ruined.
Most importantly, don't get your hopes up about the date. Try to get excited for your alternative too so that if she really doesn't reply/cant make it, you wouldn't feel like your evening is ruined.