Toni Hryziuk, 30, and her victim Michelle Hryziuk had been in a nine year relationship but it had come to an end before the incident, Preston Crown Court heard, with the women still living together and caring for their daughter.
The court heard the defendant, of Leyland Lane, Leyland, began to suspect the mum had formed a new relationship, and the former couple got into a mutual physical fight following a party at their home in July 2018.
Prosecuting, Rachel Woods said: "Because of difficulties with finances they had to remain in the same house they shared with their child. As one can imagine it's not an easy state of play.
"They had a party that afternoon and the defendant had suspicions her ex had formed a new relationship.
"Both claim the other was more drunk than the other, but a witness gave a statement the victim was drunk and the parties had seemingly been having an argument upstairs.
"The party had finished by 11pm. It was clear that there was simmering pressure between the parties and the defendant went on to tell police she suspected the victim had been sneaking upstairs to use the phone."
During a further row the victim admitted she was seeing someone.
They began to fight, with both suffering injuries, and when the victim ran into the dining room the defendant pulled her backwards by her T-shirt, causing her to fall and strike her head hard.
She realised she was quite seriously injured and called an ambulance, telling paramedics there had been an argument, that she had hit Michelle once and Michelle had hit her head on the floor.
But as the paramedic was talking to her, the woman's facial injuries appeared to be developing, including two black eyes, and swollen nose and cheekbones.
Philip Holden, defending, said the defendant, an education support worker who is currently furloughed, is likely to lose her position.
He added she had herself suffered a cataract injury in the fracas, leaving her needing glasses.
Hryziuk admits wounding.Judge Andrew Jefferies QC imposed a 12 month community order with a rehabilitation requirement.
He added: " Your jealousy got the better of you. That led to a fight.
"It ended with you pulling on your ex partner's T-shirt causing her to fall heavily to the floor in the process - not intended by you - causing the cut to her head."
He accepted since then there had been "civility" and they had been amicable.
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