(KRON) – A San Jose family is mourning the death of a beloved daughter and sister after she died from a suspected fentanyl overdose. The mother of 19-year-old Crystal Martinez told KRON4 she does not believe her daughter knew that the pill she took contained the lethal drug.  Martinez died on Saturday, Nov. 9 after coming home from work.  Her mother, Estela Martinez-Mendoza, said she was lying down on the couch when her 11-year-old daughter approached her to say Crystal was sleeping and would not wake up. Martinez-Mendoza went to check on her and could also not wake her up. She performed CPR and called 911. Paramedics pronounced Crystal dead.  According to Martinez-Mendoza, Crystal received a pill from a friend after telling them she had a headache. When police officers arrived at the scene, they told Martinez-Mendoza they found pills that looked like Tylenol but suspected that they contained fentanyl.  Over 60 grams of fentanyl, 100 grams of meth found in search warrant Martinez-Mendoza is still trying to figure out exactly who gave her daughter the pill. She is waiting to hear back from the San Jose Police Department about its investigation.  “To be honest, I don’t think she knew what she was taking because through the week she told me she felt overworked,” Martinez-Mendoza told KRON4.   Crystal was working two jobs – as a caretaker and at BJ’s Restaurant and Brewhouse. Her mother described her as strong, lovable and caring. Before her death, Crystal had planned a “sister date” with her 11-year-old sister at the mall.  “Crystal was a very happy person. Always caring. She liked to take care of older people,” Martinez-Mendoza said.  After her daughter’s tragic death, Martinez-Mendoza has a message for other parents – always keep your children close, even as they grow into adulthood.  “We have to be really careful with our kids, with our teenagers, even if they are 18 or 19 years old. We got to be careful and see who they’re hanging around with, sit down with their kids,” Martinez-Mendoza said. "Check their backpacks, purses, cellphones." Mendoza-Martinez has set up a GoFundMe for Crystal’s funeral expenses.