Taking to her social media, the 21-year-old posed for a mirror snap with beau Max George as she clutched her swollen belly.
She later revealed it was all a prank and that she had just eaten a "five-course meal".
Writing in her column in The Sun, Ulrika Jonsson slammed the "foolish" pair and called them both "unwanted".
"In many people’s eyes, this was a pregnancy announcement," she said. "Little wonder then that the smug couple faced a backlash."
She added: "I get that people don’t think messing around and pretending to be pregnant is funny.
"Especially for those who have struggled with, and maybe lost, the battle with infertility.
"While I have no desire to defend these two young fools, it should also be possible to josh around a bit once in a while, right?
"What really got my goat was the fact that, once again, this publicity-hungry couple did it all for attention.
"This was all about creating a stir, getting noticed and making sure they kept their names in the news.
"And, naturally, they got what they wanted. It’s just that in my life, they’re very much The Unwanted."
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