UPDATE: Police confirm the pair have been found, safe and well.
WA Police Force and Department of Communities are concerned for the welfare of three-year-old Eva Lee Cooper and 22-year-old Nicki Lee Cooper.
The pair were last seen at the Mandurah Foreshore around 11am on Tuesday.
Nicki is described as fair skinned, medium build with blonde hair and blue eyes. She was last seen wearing a black t-shirt and black pants.
She is in company with three-year-old Eva Lee Cooper who was last seen wearing a pink and blue Peppa Pig top with pink leggings and no shoes.
Anyone who sees Nicki or Eva should contact WA Police immediately on 131 444.