Lady unexpectedly eavesdropped the owner of the restaurant, who was scolding the staff. (?)

подслушала - я бы сказал overheard

Спасибо, Ник. Это слово, конечно, я рассматривала.
Нграм почему-то "утверждает", что eavesdrop популярнее...

распекать = dress down

eavesdrop имхо больше подойдет, если целенаправленно подслушивать, а overhear - если случайно

Это очень полезная информация, спасибо ещё раз.

I accidentally overheard the owner of the restaurant scolding the waiter

The lady accidentally overheard how the waiter got a good dressing down from the owner of a restaurant.

Анна, спасибо за ваш вариант.

https://books.google.com/ngrams/graph?content=told+him+off%2C+dressed+him+down&year_start=1800&year_end=2019&corpus=26&smoothing=3&direct_url=t1%3B%2Ctold%20him%20off%3B%2Cc0%3B.t1%3B%2Cdressed%20him%20down%3B%2Cc0

OVERHEAR is normally used for exact words: "Zoya overheard Uly giving Ross his telephone number" - if you can repeat what you heard, you OVERHEARD it.

For example, you can HAPPEN TO HEAR two people having sex, but you wouldn't OVERHEAR them, because you can't repeat what you heard 😅

However, you can overhear AS someone is doing something or THAT someone is doing something

That was the most difficult translation I have ever worked with.
Honestly, I wasn't expect English so difficult language!))

Thank you!

English is very nuanced, but then so is Russian))