No no , she did run away from home but they arw not siblings they are like siblings but they are not siblings (〜￣△￣)〜
That lil boy is her neighbour, I think. The boy's room is just across Wendy's room. That's why he call him sister? I think.
Idek ╮(￣▽￣)╭
Since it's korean I think he calls her "nuna", like girls would call older girls "unnie", even if they're not blood related
Asian thing don't worry
Wait. I dont understand, she has brother? Was not she just run away from home and started her own business?