if you are interested in her then by all means --call her
If you're talking about dating I think it's better to act interested than aloof unless you just like games. Still, give yourself to time to compose a thoughtful response if it is required.
same day responses aren't too eager in my opinion...especially now that everybody is texting all the time
I'd wait two days.
...you don't know the reason for the reply taking two days I take it? i would advise not to start of playing games like *** for tat. or on second thought....do that...its best to be yourself........see how long that works for ya. ;) So many of you think way too much.