A Bronx mother claims her child was sexually assaulted at a homeless shelter.The mother says her 3-year-old daughter was assaulted by another child at the shelter on East 211th Street. She claims she left her daughter with a neighbor she knew and trusted.The girl's mother says after the neighbor went to sleep, the neighbor's 9-year-old daughter committed the assault. The alleged victim's mother believes there could be other victims as well.The Department of Homeless Services says it is fully cooperating with police during the investigation.