The two stars were spotted promoting their respective clothing and hair piece collections at the fair to style conscious guests, including former TOWIE cast members Lauren Goodger and Danni Park-Dempsey, as well glamour model Aisleyne Horgan-Wallace.
Abi looked ultra glam for the evening in a figure flattering black dress, which featured a sheer layer over the top for a sexy, yet subtle twist.
She styled her hair in huge golden curls and completed her look with a pair of black peep toe heels and a chunky gold watch.
Supporting Abi on the evening was her BFF and TOWIE co-star Jasmin Walia, who also used the fashion fair as an opportunity to hang out with Frankie and Aisleyne, as she later tweeted: "Haha nice catch up with @FrankieEssex and @Aisleyne1 tonight xx"
Bubbly blonde Frankie spent the night schmoozing with guests and working hard on her stall, promoting her range of hair pieces and extensions.
She donned a chic cream dress, which featured capped sleeves and teamed it with a pair of gold, strappy heels and a gold heart pendant necklace.
Meanwhile, former Big Brother contestant Aisleyne looked funky in a red, white and black striped bodycon dress and red heels.
It sounds like the girls had a great time together and it was all for a good cause too, as Frankie tweeted afterwards: "Had the best night tonight hope we all raised lots of money for Haven House..."
Although the TOWIE star has been keeping busy with her hair piece business, no doubt her mind has also been occupied with thoughts of her little brother Joey Essex, who has now landed in Australia to take part in this year's I'm A Celebrity... Get Me Out Of Here!
Joey was seen bidding an emotional farewell to his Essex pals and ex-fiancée Sam Faiers on Wednesday night's episode of TOWIE (13 November) and admitted that he would miss hanging out with the boys in his hometown.
However, he was also heard saying that he thought the distance would be beneficial for him and Sam, so that the former flames could finally move on. Aww!
What do you think of Abi and Frankie's outfits? Let us know below, as the best comment each week wins £50!