Question about discussing other student's progress in the lab with advisor

[academicaccount]

This issue falls to how my lab handles collaborative projects. If the grad students are writing an abstract for a conference, then the grad students pass it back and forth between each other and provide edits and feedback before sending it to our advisor. My issue is that the first author (4th-year Ph.D. student) is making blatantly wrong statements and misinterpreting the data. Additionally, the writing is typically very poor. As the second author, I (Ph. D student) see these things, provide comments for some things and edit others. For this last abstract, I had to rewrite the entire results. This has happened for several abstracts and papers. As a side note, this is not an authorship issue, I've been first on several.

My question is: should I discuss these issues with my advisor? He has never seen the student's nonedited work. I think at this stage of her career, she should not be making these mistakes. Additionally, it falls back on me since I am an author. I recognize that I am not a perfect writer, so when fixing a lot of the other student's issues I tend to miss other issues when it is sent to our advisor. Therefore, our advisor weighs the mistakes equally. I just feel as though it is not my role to teach this student how to write and interpret data when I am still learning myself. Thoughts? Has anyone else experienced a similar situation?

[AP]

I don't think it's up to you to decide how someone's writing should or shouldn't be at "this stage of her career." This is not to say you shouldn't do anything. As a colleague, you should approach the other student and politely have a conversation with her (while probably suggesting possible resources, like a writing center on campus). Writing is a an uneven skill that not everyone masters at the same pace or in the same way. 

I've been in your colleague's shoes, writing not so well. I benefited from a fellow grad student pointing out "silly" but overtly huge mistakes. Today we send each other drafts all the time because we trust we are honest, thorough, and kind.