After losing her pet, she became more closed-off and stopped talking about her feelings with anyone.

closed-off 是由动词 close（关闭）和副词 off（离开、断开）组成的复合形容词。close 表示"关闭、封闭"，off 表示"断开、隔绝"。 closed-off 形容一个人对外界封闭、不愿意交流的状态，指"封闭的、不愿敞开心扉的"。