I like the idea of joining yourself because you said that you ordered more when you got the discount! Why not be your own customer!!!! No feeling hurt because you would be signing up under your friend I assume but one word of caution with that, if she isn't a good demo, will she be a good upline??? That is important! If you ever wanted to grow your business, a good upline is key!
If she is your friend, then the best option is to talk to her about it. Maybe she really doesn't want the hassel of having "customers" so to speak or she might feel as though telling you she is ordering is being pushy, but it is something that you can find out how she feels by talking to her. Do you take classes from her or anything other than ordering?
If that option doesn't appeal to you, find another demo that you can place orders online from and have shipped to you and then place the occasional order from your friend. Saves the friendship but keeps you happy too!!!!