(I tried on the wheelchair...I couldn't make it look quite right, so I tried to use some perspective to make it look at least passable...I hope I didn't fail XP)
She is probably the opposite of Seph. She's quite quiet and prefers dresses to trousers. She likes dressing up and quiet things a lady of the time should like, unlike Seph, whose hobbies as a child were fencing and horseback, Diana tended to like reading, writing and playing piano (something she was once very good at, but can no longer do). All their differences aside, Diana loves her sister more than anything and can't wait to see her again.
This is Diana Riverfall, Seph's younger sister by six years. Present day, she is fifteen years old. She's in a wheelchair because, thanks to her father's experiments, she lost almost all use of her right side. She can't use her right arm at all and her right leg is very weak, she can only stand for a few moments without assistance, unless she puts her weight on her left leg and even then, she's not able to stand for too long. So, most of the time, she's in a wheelchair.
