Is my coworker's overachiever/hustle culture attitude making me look bad?
I have a nice white collar job, with a good manager and one other coworker in my department. My job involves some travel, standard work, and special projects. I get to WFH more than half the time. My workweek is 40 hours, and I keep to that. It is not a standard 9-5, in that I have a lot of flexibility in deciding when I work during a day (as long as the work gets done). If I am traveling, then I do less standard work/projects that week. My job is pretty much a dead-end position, and has almost no promotion possibility (which I am fine with). I like the work-life balance, and my pay is industry average. I have family to take care of and and other commitments, so I am happy with this gig.
My manager is supportive and usually laid back. He respects my vacations, time off, etc., and evaluates me fairly. I keep a good but professional relationship with him.
However, my coworker is very assertive and aggressive. Not in a mean sense, but in a try-hard, hustle culture sense. She is single and does not have any family/outside commitments. Her emails go out at all hours of the night and on weekends. She will do the same amount of standard work/special projects of her own, even if she has been out for a couple of days traveling during the week. She has recently begun to work on things that I have been doing. She has even taken on special projects which I have proposed to do, but have not done immediately, because I was busy doing other work during my 40 hours. Based on the amount of work that she is doing, I think she's probably working 60+ hours a week. She told me that she is aiming for a promotion and raise, but like I said, our positions are not where people get promoted from, and I do not know how she can get a higher raise (I do quality work, but stick to my 40 hours/week schedule, and got the highest raise this year). So I do not know why she is doing this, other than because of her personality.
Now I fear that she is making me look bad/lazy. I also don't want her hustling to make my workplace set our goals higher than what they are now, which are reasonable and achievable. My manager is busy with his own work at the moment, so I do not think that he has noticed this yet. But I feel that sooner or later, the difference in results between what how much each of us are doing will be noticeable. I do not trust to have any kind of “discussion” with her. She has acted manipulatively before, like telling me that the boss said something when he did not, or telling the boss that she talked with me about something when I did not. Neither of us has anything to gain by hurting the other, but I do not doubt that she will talk badly about me if it makes her look better or look like a hard worker.
What should I do?