This is the 16869th most frequent Russian word.
совершила
"Совершила" translates to "committed" or "accomplished" in English.
Here, 'совершила' means 'made' or 'committed' referring to performing an action, specifically making an error.
Она совершила ошибку в расчетах.
She made a mistake in the calculations.
In this context, 'совершила' refers to carrying out an action with purpose, such as taking a walk.
Группа совершила прогулку по парку.
The group went on a walk in the park.
Here, 'совершила' means 'completed' or 'executed' in the sense of accomplishing an activity or task.