My girlfriend sewed a button on the sleeve of my shirt for me.
One of the buttons on the sleeve of my dress shirt fell off, so I asked my girlfriend to stitch it back on for me.
この場合、次のような言い方ができますよ。
ーMy girlfriend sewed a button on the sleeve of my shirt for me.
「彼女がワイシャツの腕のボタンを縫ってくれた」
ーOne of the buttons on the sleeve of my dress shirt fell off, so I asked my girlfriend to stitch it back on for me.
「ワイシャツの腕のボタンが1つ取れたので、彼女にお願いして縫ってもらった」
ご参考まで!