уже стоя у кассы, она вдруг вспомни

уже стоя у кассы, она вдруг вспомнила, что забыла купить молока, и пошла назад к прилавку с молочными продуктами.

Результаты (английский) 1:

already standing at the cash register, she suddenly remembered that I forgot to buy milk, and went back to the counter with dairy products.

Результаты (английский) 2:

already standing at the cash register, she suddenly remembered that she had forgotten to buy milk, and went back to the counter with dairy products.

Результаты (английский) 3:

Already standing at the cashier's office, she suddenly remember that forgot to buy milk, and went back to the counter with dairy products.