I am certain there is s way to prepare everything you may need by tonight if you truly wish to ask her in the proper manner.
[He has to think about his answer for moment.] Offended may not be the right word, but it is very possible that you have embarrassed her greatly! Not to mention the fact that you have asked her where anyone can hear may have some influence in her answer. She may feel guilty if she rejects you over the network and feel forced to accept. On the other hand, she may now feel too embarrassed to accept and make the rash decision of saying no without truly thinking her answer through first.