I guess- just stick to the base lines that she's really shy and introverted. I really hadn't depicted her backstory as anything too bad for the character- (for example, she didn't lose 10000000 people she cared about and she wasn't homeless despite being an orphan blah blah blah jgbnjfghfjgjfthfd-)
To be honest, when I first created her, I literally didn't think she really had a backstory. Pretty much her whole backstory was the fact that she always was a rich orphan who lived in a mansion alone. She, in RS, is actually just a background character who was kinda cute at the time.