ihateyounot As long as the feedback is constructive not destructive, that's all good. Constructive feedback is golden to an inspiring author.
There's also providing feedback on the the story itself for plot holes, character impressions, flow and so forth. You can have a story that is grammatically sound, but lacks on storytelling conventions and mechanisms. Usually, this is more important to a writer than picking out their grammar. Grammar can be eventually fixed in final draft stages.