Can I disclose to others that my sister is on medication for ADHD?
Why would you tell everyone about your sister's ADHD meds?
I just want my sister to have a normal life with everyone.
I understand that you are concerned for your sister, but it is inconsiderate to tell people her personal medical history. Keep your silence on your sister's condition.
It's not like she's mentally ill.
She might not be but it is not your condition to disclose. It might make her uncomfortable to know you have been spreading it around. It's also rude to tell someone else's medical issues.