The thirty year old was found stabbed to death in her burning house in west Belfast on Sunday.
Hundreds turned out to pay their last respects at her requiem Mass at Christ the Redeemer Church in the Lagmore area of the city.
Parish priest Fr Martin Graham said: "Whoever did this to Jennifer has turned her death, which was cold-hearted and callous already, into something that was wicked and obscene.
"A family home has been destroyed as her family's hearts have been torn apart."
Friends and family gathered in bright clothing for the hour long church service.
They heard Ms Dornan described as a fun-loving and outgoing person.
Fr Graham said: "Jennifer was a vibrant human being with a love of life and a joy and energy that attracted many friends. She enjoyed life so much and she was the life and soul of any party.
"Jennifer knew what she meant to a great many people and she enjoyed company. She was quick and razor sharp in mind and in tongue.
"She gave everyone plenty to laugh and smile about and she never had to try hard.
"Her nature, her personality, was one that even with her own troubles and worries she could still smile and help others to do the same.
"This world is the poorer now that Jennifer has left it, and with her buoyant personality it will also be so much quieter."
Ms Dornan leaves three children - Martin, Jayden and Abi, all aged under nine.
An online campaign to raise funds for the young family generated more than £10,000 in just 48 hours.
Police confirmed they'd launched a murder investigation on Monday.
A 39-year-old man was arrested earlier this week on suspicion of withholding information. He has been released pending a report to the Public Prosecution Service.
Police also released a picture of a replica of what they believe to be the murder weapon.
