Joanne Binns, 42, was last seen at about 3.15pm on Monday last week when she got a taxi to the Hyde Park area of Leeds.
Officers have now released CCTV images of Joanne and her nine-year-old son at a cashpoint at the Co-op store in Seacroft on the day she went missing.
Detective Inspector Mark Strother, of Leeds District CID, said: “We have been making extensive enquiries to trace Joanne and her son who have been missing for over a week now and we remain very concerned for their welfare and urgently need to establish their whereabouts to check that they are okay.
”We hope these new CCTV images will give people the most up to date picture of what they look like. We would urge anyone who has seen them or who knows where they might be to contact us immediately.”
She is described as white, 5ft 3ins tall, with short brown hair.
Anyone with information is asked to contact the Special Operations Room at Elland Road via 101 quoting log number 762 of September 15.