Formal charges are expected Wednesday against a Helena mother accused of killing her three-month-old twins. Rosie Mary Davis was arrested yesterday. The 23-year-old was being held in the Phillips County jail in the deaths of her children, Daniel and Danielle. Police Captain Johnnie Davis says the mother called 911 yesterday morning and reported that she had found her children dead. Davis says the mother was arrested based on statements she gave to investigators. He would not comment on cause of death or a possible motive. The bodies were sent to the state Crime Lab in Little Rock for autopsies. Davis says it appears the infant son was killed some time before his twin sister.