Why would a girl do this????

Some girls play hard to get but sometimes feels confused..And for what you are explaining I think she likes you but doesn't really know how to show you or tell you. Maybe she needs to know if you like her cause she is probably thinking the same way you do..If your conversations are for 40 minutes then how can you not talk to her on a sincere level..Let her know that you want to know more about her this way you can find out how she really feels about you. Good luck.