Erin Lee Macke of Iowa left two 12-year-olds, a seven- year-old, and a six year-old at home, while she was away.
Police say she made no arrangement for child care and left a firearm so the children would have access to it, New York Daily News reported.
She was arrested by Johnston police on Thursady.
According to a statement, police were called to Macke's home on September 21 following a report that children had been left without adult supervision.
The Iowa Department of Human Services came to get the children, while police called Macke and ordered her to return home from Germany.
Police said Macke was arrested on four counts of child endangerment and one count of making a firearm available to a person under the age of 21.