And it wasn't exactly the TV introduction to the country that she might have wished for.
The brave contestant actually put on weight while wearing less than flattering lycra clothing.
"It wasn't a pretty sight next to the beautiful Kathryn Thomas who has a lovely slim figure," Deirdre said.
"The weighing process is definitely not ideal and certainly wasn't nice, but it's part of the process and it's done now," said the mum -- who is two weeks away from her 33rd birthday.
It is a far from ideal situation for the leaders as they step up onto the weighing scales in front of the Irish public.
Deirdre was the first up on the scales to find that she had put on a couple of pounds since last November.
"The weigh-in outfits are horrendous and awful," laughed Deirdre, who hails from Co Cork.
The dreaded weigh-in will take place every week for the leaders as they attempt to hit their target weight loss.
And there is no escaping the bulge for the girls who must wear skin-tight leggings and a sports bra, while the men wear bicycle shorts.
"You have nowhere to hide as the clothes make it very hard to hide big arms or wobbly bits," said Deirdre.
But it is all a part of the process, says upbeat Deirdre, who is proud mum to her two little boys Jack (2) and Cian (four months).
"I understand why they do it, it's a wake up call like never before," added the young mum, who is hoping to add some glamour back into her life.
Deirdre, who now weighs 14 stone 6 pounds, has put on two pounds since she was weighed last November.