Writing a letter of recommendation for a promising but very new student As part of my PhD I am required to teach some bachelor level micro and macro economics classes. One of my new students (we only had 3 classes together) approached me with a request for a letter of recommendation for summer research internship.
The student looks like good student, they are active in class and pay attention and asked few good questions. However, I only talked to the student 3 times in my life during the online classes.
This creates a conundrum for me because the student so far made a good impression on me but I know nothing about the students and first impressions can be deceiving. In addition, one should of course never lie on the letter of recommendation so the best I can say about the student is that I recommend them because they are active in the class and ask good questions.
Also, the student said that they need to submit application by end of next week so I will see the student only once more in class and by that time the students won't even submit their first assignment for the class. So waiting here and seeing how the student will do is not an option.
Consequently, my questions are:

Would there be any possible repercussions for me if I write truthful letter of recommendation, but the student turns out to be very bad at their internship? In another words would that cost me my creditability, are recommendations for candidates in academia taken very seriously?
Would writing such recommendation help the student at all or would it actually potentially hurt student's chances?

I know this is a topic that was already discussed at academia, for example here but that does not answer my question because the question is about mediocre student whereas this student looks promising.
As suggested by @academic in a comment, I think this is a case where you should decline to write the recommendation (and do so as quickly as possible so that they can find someone else) and suggest they ask someone with whom they've had more interaction.
I think it may end up normal for students during the pandemic to rely on recommendations from instructors they have had less interaction with due to the obstacles of online learning, but here you're talking about someone for whom you can't even refer to their performance on a single assignment.
If you wrote a letter that was honest, really the best you can do is to write what you've said here: this student meets expectations for an attentive student in the limited interactions before the first course assignment is due. I can't imagine that letter filling any positive role besides checking a box towards &quot;x/N letters submitted&quot;. If acceptance for the internship is competitive then the letters written for this student will be compared to letters written for other students, and a non-robust letter like yours will probably compare unfavorably.
Additionally, as a PhD student you might also suggest to the person asking you for a recommendation that they get letters from professors rather than graduate students. It's possible that the distinction isn't as important for this internship, but generally references from professors are preferred. When I was a graduate TA I would occasionally co-write a letter with a professor in charge of the course I was teaching: the letter would come from the professor, but I'd add my own paragraph that the professor would incorporate into their letter. I don't suggest you use that for this situation (and it doesn't make sense if you are the instructor of record rather than a TA), but something to keep in mind for future requests.