Also she had the power of silent sympathy.

That sounds rather dull, I know, but it's not so dull as it sounds.

It just means that a person is able to know that you are unhappy, and to love you extra on that account, without bothering you by telling you all the time how sorry she is for you.

That was what Bobbie was like.

She knew that Mother was unhappy--and that Mother had not told her the reason.