A passerby noticed the two girls in the backseat about 2:10 p.m. and unlocked a car door through an open window, police said. The passerby took the two girls, who were not injured, into the store for safety, police said.
Also, the baby was not in a proper child restraint seat, police said.
The girls are not related, police said.
A man who answered the phone at Erwat's home Monday night said she was sleeping and could not come to the phone.
But he said Erwat did not leave the girls alone for long.
"She just went to the bathroom," said the man, who identified himself as her husband, but did not give his name.
When asked why she did not take the girls with her, he replied, "They are so small, you have to carry the baby into the bathroom and there is nowhere to place them and all that."
Erwat posted bail after being charged with two counts of endangering the welfare of a child and will be arraigned later at First District Court in Central Islip. The arraignment date was not immediately available.