Meaning of ばかり in a sentence from a book


I am reading the book 鵺の家 by 廣嶋玲子 and I have a question about a particular
usage of the word ばかり. One character (千鳥) complains to the main character (茜)
as follows

> 仲良く付き合っていきたいわ。お兄様もお義姉様も、自分のことばかりのそっけない人達だし。私、寂しいのよ。

What does ばかり mean here and how it relates gramatically to the rest of the
sentence? Does it mean "always"? But then why it is not written like this:
自分のこと(が/を)ばかり（ずっと）そっけない人達だし。




This ばかり means "only", but working as a (no-)adjective.

You can read 自分のことばかりの人 as "自分のこと-only people", or people who are only
interested in what concerns themselves.




This ばかり means "only", but working as a (no-)adjective.

You can read 自分のことばかりの人 as "自分のこと-only people", or people who are only
interested in what concerns themselves.

