The photographer, who is married to Virgin Media host Martin King, shared the news on social media.
“I’m going home. Please God I don't have to come back!” she said.
She underwent an operation last week to have a tumour removed from her brain.
While the procedure went well, Jenny took to Instagram on Monday morning to explain that she had to return to Beaumont Hospital because she was in a lot of pain.
“Can't believe I had to come back to Beaumont,” Jenny wrote alongside a crying emoji.
“Please say a prayer that they can manage the pain for me,” she added.
Jenny was discharged from hospital just days after the life saving surgery to return home and relax.
“And just like that, Professor Ciarán Bolger decided to let me home to relax. I've never been so grateful, grateful to have the last week behind me,” she shared.
"It looks great, just one more little test to come back. But for now it's time to chill out on the couch and start the road to getting Jenny back to where she actually belongs."
Jenny recently revealed that a brain tumour removed in 2011 appeared to be growing back.
She opened up about her news in January, revealing to her Instagram followers that the tumour may have begun to regrow.
“Hello Everyone. So, I have some news… not the best news but not the worst news either.
“Some of you may already know that I had a brain tumour removed successfully in 2011 by an incredible person, Professor Ciarán Bolcer at Beaumont Hospital.
“Unfortunately, after a recent brain scan, it seems there is new activity. This means there is some ‘swollen tissue’ which is probably the tumour growing back.”
However, she had “good news” after speaking to experts, adding: “Good news is, it’s not malignant and Professor Bolger will need to carry out some more brain surgery to remove it.”
“Ciarán has assured me that after surgery, I will need to take six weeks off but after that I’ll be back doing what I love and that’s documenting weddings, newborn baby & portrait shoots and of course, bringing out more incredible wedding and baby products.”