Is it normal that my friend now expects me to pay for her after i paid for it?
a while ago i purchased some one dollar eye shadows online while we were browsing the internet together. we found this shop where you could get eye shadows for 1-3 bucks. so that one time she ordered an eye shadow along with my batch of make-up so she could save on shipping and handling, which is okay. when the package arrived, i said she didn't need to pay for it ($1) because she's been my friend for so long and i just wanted to do something nice once in a while. now whenever i shop online at the one dollar store she always wants to tag along, she asks me when i'm going to be ordering again. i'm worried that she's expecting me to pay for her again.
did i make a mistake by letting her have her order for free that one time? as background information, i'm talking about this same person: http://isitnormal.com/story/is it normal that-a-friend-pretends-like-she-doesnt-about-your-hardships-100918/ so understandably i'm very worried that i've made a mistake.
please help? on one hand, i don't want to lose a friend, but i also can't afford to be her "sugar momma". was i wrong to want to treat her when there was NO SPECIAL OCCASION? when you pay for someone once (and not during a special occasion), is it normal that they take it as a sign that that i'll pay for their stuff again in the future?