を作ってあげた

made ... for someone

→ を

phrase Rare #21,019

made ... for someone あげた shows that the speaker did the action as a favor for someone else. を marks what was made; the person it was made for is usually marked with に.

JA: 妹にケーキを作ってあげた。

EN: I made a cake for my younger sister.

あの子にお人形さんを作ってあげたの。

I made a doll for that child.

彼女は彼に新しいコートを作ってあげた。

She made him a new coat.

私は彼女にドレスを作ってあげた。

I made her a dress.

彼女に人形を作ってあげた。

I made a doll for her.

彼は彼女に新しいコートを作ってあげた。

He made her a new coat.