No. Such topics are inappropriate for public discussion as they involve private and often sexually explicit content that violates public decency standards.
One way is to use strict content filters on platforms. For example, social media platforms can set up algorithms to detect and block such vulgar content.
A great alternative could be a story about friendship. For example, the story of two friends who support each other through difficult times. They might go on adventures together, face challenges, and grow closer as a result.
It could be normal if you both have had open conversations about sexual preferences and fantasies. If you are okay with her exploring her sexuality in this way and she feels comfortable with you being aware, then it can be a normal part of your relationship dynamic. But if it makes you feel uneasy or if there hasn't been proper communication, it might not be a healthy situation.
Well, it could be that she was exploring her own sexual desires in a solo way. Maybe she found that the black dildo had certain features she liked, like its shape or texture.