Hollie Thomas, aged 35, lashed out after downing vodka, before phoning an ambulance and claiming "it was an accident".
Shrewsbury Crown Court heard that Thomas, the victim and another woman were at the house in Telford and they had drank a "significant" amount of alcohol between them - two bottles of vodka.
Thomas went upstairs before coming back down and slamming the glass into her former partner's head in a rage. He was left with cuts to his face and ear.
She was later arrested. Meanwhile, her ex-boyfriend lost three weeks of work costing him around £1,000, and said he suffered a "loss of confidence" as a result of the incident.
The court heard that the pair were on good terms again, until the victim refused to hand in a retraction statement over the attack.
Thomas, of Haybridge Avenue, Hadley, Telford, pleaded guilty to unlawful wounding.
Debra White, mitigating, said: "This is clearly an offence that was fuelled by alcohol." She asked for the court to take into account how long the case had taken to be resolved and the fact that Thomas has childcare responsibilities for her son.
Judge Peter Barrie told Thomas: "This was an unprovoked attack on your former partner. You probably had some sort of an argument. You used a glass. Mercifully, it didn't break.
"He may have made a full recovery from his injuries, but he changed his job, lost out financially and moved away from the area."
He handed Thomas a 10-month jail term, suspended for 18 months. He also ordered her to pay her £500 in compensation and made a restraining order, banning her from contacting her ex for five years.