The important part to remember is everyone has a life. 3 days per text probably is on the higher side, unless needing to screen, wait for other parts of life / schedule to come through, etc. I wouldn't be disinterested over an occasional 3-5 day turnaround, but, she also has to know you may be pursuing other options. Usually if you're being efficient and not still screening 6-24 hours may be normal, again, everyone's got their stuff though.  
 
Patience is often rewarded, and overtexting never is, but, I wouldn't hesitate to send a reminder after several days myself. Sometimes I just send a nice text saying sorry for the additional text, I just have to make sure I block off time for this, and really hope we can get together, but if not this time in the future. Never had someone not respond kindly to something like that, but I only do it once. Seems to let her know too you've got a limited window if interested may respond sooner.  

Yeah, makes sense.  

I've been careful to only text in reply and sent one reminder  -- I also think it is because of how far into the future it is and the screening process to boot.