The Chester County district attorney's office alleged that Jessica Lynn Riffey, 34, of West Caln Township, supplied the 14-year-old girl and a 16-year-old boy with heroin and injected them multiple times last month.
Riffey was charged with corruption of minors, endangering the welfare of children and drug delivery. She was jailed in lieu of $50,000 pending a preliminary hearing Friday. Online court records didn't list a lawyer who could comment on the charges.
Prosecutors also allege that Riffey's boyfriend supplied heroin for the teens to snort. He has been charged separately with drug dealing and other offenses.
District Attorney Thomas Hogan said the family lived in a trailer in which numerous people were using heroin. He said the mother was supposed to be caring for and protecting her daughter and instead exposed her to the drug and enabled her use of it.
"it's hard to make that leap as a parent, to think how you end up in that position," he said.