The gorgeous reality star, 24, embraced the fancy dress element of the spooky day in her usual way - stylishly!
Billie chose a sexy black trouser suit which hugged every inch of her fabulous post-baby body.
Teamed with towering black heels, she only needed one little accessory to give the outfit a playful twist... Some cute bunny ears.
Unsurprisingly, Billie's fans were quick to tell her how great she looked.
One said: "Look at her after having a baby. She's fab!"
Another wrote: "She's stunning. I love her."
Billie also posted a super cute photo of her Saturday night in (1 November) with daughter Nelly.
She wrote: "Early night for me and Nelly noo doing some internet shopping watching #xfactor..."
In the snap, Nelly's little legs can be seen on Billie's bed dressed in a pink babygro.
Next to her on the bed is Billie's laptop... We bet she was buying more clothes to look hot in!
We love your style, Billie!
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