Emma Edgington admitted intending to use it to hit another woman during disturbances in south Belfast, prosecutors said.
The 23-year-old, of Flush Park, Lisburn, pleaded guilty to possessing an offensive weapon in a public place.
Police were called to the Wellesley Avenue area on 3 June following reports of a dispute.
Belfast Magistrates' Court heard on Thursday that Edgington was arrested after being seen carrying the wheel brace. Defence counsel accepted she had made frank and "chilling" comments about why she had the weapon.
The barrister said: "Her comments are quite telling and she accepts struggling to control her anger. She perceived that the lady in question had made comments about her child and she reacted in a completely disproportionate manner and armed herself with this brace."
Passing sentence, District Judge Fiona Bagnall said Edgington could easily have been sent straight to prison.
But due to her guilty plea the four-month jail term was instead suspended for two years.
Judge Bagnall warned: "If she is back (in court) she will be in custody and be in for a long time."