Phaya Thai police arrested Wipawal Limpapornpichai and seized a number of lottery tickets and 46 tablets of methamphetamine, or yaba.
Police worked on a tip-off from informants that a lottery ticket seller was selling drugs to youngsters in the area, Theerasak Sriprasert, deputy chief of Phaya Thai police station, said.
They found the suspect at the railway station and took her to the station for interrogation.
Mrs Wipawal said she had sold lottery tickets for more than two decades but was struggling to make ends meet. She eventually came into contact with a yaba distributor who offered to sell her pills for 140 baht each.
She said she made a lot of money by selling the pills on to customers for 200 baht a tablet.
Pol Lt Col Theerasak said her trick to disguise her drug sales was to use masking tape to attach a pill to a lottery ticket when she delivered it to a buyer.
Mrs Wipawal, who was released from jail on April 29 after serving a jail term for selling methamphetamine for two years, faced charges on possessing illegal drugs.