My partner is not doing anything for our project. What should I do?

Me and my partner have a project for class. Let's call her C. C and I are good friends so we decided to work together on the project. I found out I was going to be busy this week last Friday. She was not home all weekend and still isn't to work on the project. She went to her cousin's house. I thought it was just for the weekend and coming back today, so I was okay with that, but tonight I found out she was staying another night and might not be back until tomorrow. I'm going to be busy this week because I need to work on another project with another kid and I want to hang out with someone sometime this week. I also need to go to my uncle's house for his anniversary on Wednesday. I also want to go to a nearby city just to hang out this week. I love going there and I want to go there sometime this week. I also have a doctor's appointment and somewhere else to go to on Wednesday. This is our break from school, but I'm so busy this week. Anyways, I have a lot to do this week. She doesn't even call to say that she won't be home. I had to call her to find out. She acts like she cares about this project, but she really doesn't. She says she's panicking about it, but I know she doesn't care about the project. I'm just tired of being flexible with my own schedule and I know she'll be mad when I can't work on the project this week. So, anyways, what should I do? She's not doing anything for the project and is expecting me to be flexible with my schedule. What should I do? Thanks.