我给你把主句从句拆看,你看下
the woman is Mary 's mother 这是主句 一点问题都没有吧
to whom you were talking just now 调整下语序,并请理解whom代替the woman
you were talkingto whom（the woman）just now ,看到to是怎么回事了吗?talk to sb 和某人谈话；看到were是怎么来的了吗?根据主语you选are,根据just now改成were