My baby rubs his face against my chest when he gets sleepy.
My baby often brushes his face against my chest just before he falls asleep.
ーMy baby rubs his face against my chest when he gets sleepy.
「赤ちゃんが眠くなると私の胸に顔をこすりつけてくる」
顔をこすりつけることは to rub を使って表現できます。
ーMy baby often brushes his face against my chest just before he falls asleep.
「赤ちゃんは眠りにつく前によく私の胸に顔をこすりつけてくる」
to brush を使っても表現できますよ。
ご参考まで！
カナダ 
