Leo friendships - Do I just need to stop being nice to people?

So if you've read some of my answers or questions you'll know I complain about my friends a loooot lol. Yesterday my friend emailed me and asked if I had finished my assignment and I said yes and I'll send her my work as a sample. This was an assignment due months ago! So I know she is struggling with it. We have another one due this week which I have just started and she has finished. So I asked her if she could send a sample of it (just the start) so I know how to begin. She ignored me. Today she whatsapped me and we spoke for a while and as soon as I asked for the sample she said brb, she came back, changed the subject, I asked again and she said brb. That was around 1pm, now it's nearly 10. I messaged her a minute ago that Im not going to bother bottling anything up, I happily sent her my work even without her asking and I believe she purposely dodged the question and I just wished she'd tell was, that she didn't want to give her essay instead of being a dumbazz about it. I didn't call her a dumbazz lol. She is a Taurus. Was I right in sending this message? All my friends are self-serving too, its not even just her. I don't have a problem making friends, they are just never give as much as I do and that is not enough for a Leo! What do you think?