She was at the time riding as a passenger on a motorcycle when officers moved in and stopped her.
Police said the woman initially appeared to be an ordinary commuter heading about her daily business, but a search conducted on the spot changed that assessment.
She was found in possession of three handbags containing packages suspected to be Cannabis Sativa.
Following the initial arrest, detectives extended their operation to her residence within the same area.
A subsequent search of the house led to the recovery of additional items, including a basket and a transparent polythene bag, both reportedly containing more packages of the suspected illegal substance.
The recovered substances were secured by officers and are being held as exhibits pending further analysis and legal proceedings.
Mwikali was taken into custody and booked at Muthaiga Police Station, where she is currently being held as she awaits processing and possible arraignment in court.
Police have indicated that investigations are ongoing to establish whether she was acting alone or in collaboration with other individuals involved in the alleged distribution network.
The arrest adds to ongoing efforts by law enforcement agencies targeting drug trafficking and distribution networks across the country.
Authorities have in recent months intensified operations aimed at dismantling supply chains linked to narcotics, particularly in urban and peri-urban areas.
Officials involved in the operation noted that intelligence-led policing has continued to play a key role in identifying suspects and disrupting alleged drug trafficking activities before they expand further.
While details of the broader network remain under investigation, detectives are expected to analyse the seized substances and follow up on any leads that may emerge from the suspect’s arrest.