Similar questions have been answered before. While someone may answer your question in more precision, you may be interested in those previous answers.

https://old.reddit.com/r/AskHistorians/comments/6k6afo/how_were_grimms_fairytales_received/

https://old.reddit.com/r/AskHistorians/comments/8i6c2i/did_the_brothers_grimm_make_the_childrens_stories/ (have very good discussion on the subject)

https://old.reddit.com/r/AskHistorians/comments/2maig8/how_have_grimms_fairy_tales_changed_over_the/

Thanks to /u/reginhild for posting all the links. If there is anything else that comes to mind, let me know.

I have also previously discussed this in regards to the following questions. Please let me know if there's anything in the answers I've provided that you don't understand or that you feel like I didn't address in regards to your question, because I'd be happy to discuss it with you further!

• "I've heard the Disneyified versions of Grimm's Tales Americans are familiar with are highly sanitized (RRHood and Grandma are eaten by the wolf,Snow White is about necrophilia,it's Cinderella's family, not steps- tormenting her, that kind of thing).Is this true? Were children the target audience?"
• Did the Brother's Grimm make the children's stories they collected darker and more violent than the original oral traditions?