Never leave her without any reasons or explanations..
Not only will it hurt her, but it will also tear her up into pieces. Her mind will eventually suffocate her with all these thoughts and would just slowly take her apart. She’ll constantly wonder what she did wrong, all because you left without a reason. How can someone even have the courage to walk out like that in the first place? It wouldn’t have killed you just to tell her why you’re leaving, cause that would have saved her a lot of tears.