Mum-of-two Zoe Edwards, 38, ran out in her pyjamas after the youths attacked her four-bedroom home in Worsley in Manchester, on Halloween.
She got into her silver 4x4 and chased them for more than a mile to confront the gang of between 10 and 15 boys.
Three of the teenagers told Manchester Magistrates Court that the angry mother sped towards them, before winding down her window to shout and swear.
She then fired some sort of BB gun, which hit one victim on the back and another on his rucksack.
A post was later sent from her Facebook account to one of the boys saying: "You can tell those spineless t***s you hang around with they are pathetic. Revenge is a b***h called Zoe."
Edwards denied being abusive or having any kind of weapon with her but admitted leaving her home to find out who had thrown eggs.
She also denied sending the message and claimed instead that it was her son.
On the allegations she said: "I didn't do anything like that. I was scared as I realised I was on my own in my car and had come across these teenagers."
She said her home had been targeted in egg attacks before and after the incident.
The boys admitted they did not tell their parents about the attack until two or three days after the incident with one of them even apologising for the egg throwing to Edwards' husband Chris.
Lee Bonner, defending, said this showed they had made up the story to pass on the blame for the 'nasty' egg attack.
But District Judge Mark Hadfield rejected this account and found her guilty on two charges of assault and one of threatening behaviour.
He said: "I can understand you were angry and upset at having your house egged.
"I do find that you began pursuing them and that you discharged some form of implement which made contact with the back of the two complainants."
The case was adjourned for a pre-sentence report.