At around 8.05am hours a woman, who was not known to the victim, gained entry to a block of flats in Main Street, in Bridgeton, before forcing her way into her home.
The woman threatened the victim with a knife before making off with a two figure sum of cash.
Officers understand the suspect then may have made her way north along Main Street towards Bridgeton Cross.
She is described as between 20 and 30 years old, around 5ft4 in height with a gaunt appearance. She was wearing a black and grey jacket, dark trousers and trainers. She was also wearing glasses.
Detective Constable Lucy McMillan, from the Community Investigation Unit, said: “For someone to force their way into an elderly woman’s home and subject her to such a terrifying ordeal is absolutely despicable.
“It is crucial that we find the person responsible for this cowardly crime and I would urge anyone who was in the Bridgeton area on Thursday morning to come forward if they think they may have seen a woman matching the above description or anything else suspicious.
“Local residents will understandably be concerned following this incident and there will be additional police patrols in the area to provide reassurance. If you have any concerns at all, please feel free to speak to the officers who will be happy to assist you.
“Anyone with information is asked to contact officers from the Community Investigation Unit based at Govan via 101. Alternatively you can call CRIMESTOPPERS on 0800 555 111 where details can be given in confidence.”