Have you talked to her about friendship? How it is give and take and not just give? What does she get out of it?
When my SS was about 12, his then best friend stole some game cards from him and betrayed him by selling them to other kids. SS wanted to continue the friendship and we had to put in boundaries, like SS could not bring anything there he would not want missing (so he would come home, drop his bookbag, and then go to his friend's house) and the friend was not allowed in our home. Period. Not after DH had to confront the boy and his family about the cards. In the end, though, it had to be SS who saw the boy's behavior as unforgiveable and SS needed to decide to no longer be that boy's friend in any way.
If your daughter has x money from you, can you teach her to budget? Show her how people prioritize bills and such? Then let the natural consequence be that SHE does not go to the movie, etc. if she spends all her money on people who don't return the favor? It may be hard to say "No, I'm not giving you more money" but maybe that's the way she'll have to learn.
I got burned in college buying concert tickets for my sister and her friend.
A year later, sis asked if I'd cosign their lease. I said no. I told her that she and her proposed roommate stiffed me with tickets I could not use or sell and that was my food money for a week. I was not going to be on the hook for a rental for someone who couldn't even apologize for wasting my time and money on something less frivolous. It was hard to say and hard for my sister to hear and at the time she thought I was being mean. But when it was her dime and her time, she understood. She gets it now, why I didn't cosign anything I couldn't afford myself. She learned something when I made her stand on her own.
So if it were my child, I'd talk to her about friendship and values and standing up for herself and make it clear that if she doesn't use her money carefully, that is not something I will fix. From an early age we made the kids pay back even a quarter borrowed off their allowance and we did that to try to teach them responsibility. Even now I will tell my 6 yr old, "If I spend my money on candy, I cannot buy you good food. Good food is more important than candy. I need to spend it on good food first and see what we have left over."