Translation:She just left me a comment.
Totally confused here. Not sure if I missed a previous module but the use of JUST (whether the TOUT makes it with a NOW or without) twice as in VIENT and JUSTE has me baffled. Add to this the use of LAISSER as the past tense LEFT and this one really got me. I actually put "She came just to leave me a comment" which I thought was quite nice of her.
"elle vient de laisser" = "she has just left". This is about recent past, with one construction by language:
In French: verb VENIR + preposition DE + INFINITIVE
In English: VERB in present perfect + JUST
The addition of "juste" or "tout juste" as adverbs, emphasize the fact that the action happened a few seconds ago.
If Duolingo had meant "note", they would have proposed "note", I think. And a comment is not a note. A note can be a piece of paper with something written on it, or a short letter. A comment is based on something previously said, written or done. It is actually what I am currently writing.