<human>: Could you distill the essence of the text into 1-3 sentences?

Hey all,

We're about 2 weeks away from summer break and my roommate (as in we actually share a room) is leaving to go home and work for the summer. She is leaving her furniture and not many college age kids are willing to share a room with a person they don't know, so there's no replacement. We split the master bedroom so I'll have a big room to myself all summer. We're trying to come up with a fair agreement for splitting rent. My mom's idea is that she should have to pay exactly what she's been paying because her name is on the lease and she is responsible for her part and it doesn't matter that she's leaving for 3 months. I would love to take this line of reasoning but at the same time I wouldn't be okay with it if she did that to me. I'm willing to pay a little more than I have been paying but my income is not changing. How should we go about splitting it?
<bot>: roommate who I share a room with is leaving for the summer and coming back, no replacement, leaving stuff here, my income stays the same -- how do we split rent?