Yap.Town

のことが心配なの

am worried about

→ の
phrase Rare #27,498
am worried about Follows the person or thing you are worried about. The final の adds an explanatory tone; the subject is understood from context.
JA: 私は弟のことが心配なの。
EN: I'm worried about my younger brother.

トムのことが心配なの。

I'm worried about Tom.

赤ちゃんのことが心配なのよ。

I'm worried about the baby.

成績のことが心配なの？

Are you worried about your grades?