A few hours later, when Heidi was sleeping soundly, the old man climbed up the ladder.

几个小时后，当海蒂熟睡时，老人爬上了梯子。

youdao

She is sleeping soundly.

她睡得正香。

《新英汉大辞典》

Is your baby sleeping soundly?

你的小宝宝睡觉睡得香吗？

youdao

Bothinaa Mohammed and her three children were sleeping soundly the morning of Christmas Eve.

NPR: Iraqi Family Settles Into New Life in Atlanta

Oberon had rubbed poppies on its eyes to quiet its crying, so it was still sleeping soundly when she woke.

NEWYORKER: A Tiny Feast

For us, sleeping soundly has become the Holy Grail of leadership.

FORBES: Sleepless In The Big City: Why Leaders Are So Tired (and what can they do about it)