Keating, 20, and her mother, Nicola Keating, 48, pleaded not guilty to the joint charge at Manchester Magistrates' Court.
The pair were accused of possessing canisters of Class C drug nitrous oxide, also known as hippy crack or laughing gas, in Manchester on June 18 last month.
City star Keating, who was called up to the England squad last season, spoke only to confirm her name and address and make her not-guilty plea.
Jonathan Potter, prosecuting, said the women are accused of the possession of nitrous oxide canisters for wrongful inhalation, an offence under the Misuse of Drugs Act.
Keating became the youngest player to win the Women's Super League Golden Glove award in May after keeping nine clean sheets in 22 games for second-placed City.
Keating is still waiting for her England debut after being an unused substitute during the recent Women's European Championship qualifiers against Sweden and the Republic of Ireland.
Nitrous oxide was made a Class C drug under the Misuse of Drugs Act last November, as part of the Government's anti-social behaviour action plan.
Possession of nitrous oxide, where a person intends to inhale it for a psychoactive effect wrongfully, is now an offence.
It is still possible to use the gas for legitimate reasons, such as in catering or pain relief during labour.
Magistrates granted Keating and her mother unconditional bail and adjourned the case until September 10 back at the same court for a district judge to fix a date for trial.
