Hi Mandy,
Thank you for reading and for sharing your experience. Honestly, for me I think intention is key. Writers have never been limited to our own experience for characters or situations. To add in a token character from any minority is wrong, and to assume that you 'know' another person's experience and can write their voice is also wrong, but to have a character form in your mind as happen to be from a minority... well then you do the diligence you would with anything else in your book. Read others, talk to people, and create a character who is rich in detail.
Sadly if white writers never included characters from under-represented groups, the majority of readers would rarely come in to contact with them within the pages of a book.