I texted a HB8 (i went out with her last week and it was great and there is enough confidence built to ask her out on a text) "hey, my friends and i are gonna by hitting the casino this thursday, you should tag along. Bring a music cd so you stop complaining about my music."

She responded she couldn't because she has to wake up early and be in "good shape" on friday because she will be babysitting... (i sense a lame excuse here?)

I didnt respond to her text.
So my question is... should i stop any contact with her for a while? how many times is it acceptable to ask a girl out?
and finally, would it be a BAD idea to invite her skiing this weekend for the day? (ie: too soon?)

Thanks a lot in advance for your help.