The 14-year-old, who has cerebral palsy, had the judges and audience in stitches of laughter with her stand-up routine in the third live semi-final of the ITV show.
Eva, who is originally from Darlaston and now living in Cannock, pulled plenty of jokes out of the bag - including several digs at Simon Cowell.
At one point, Eva poked fun at Simon's past use of Botox as well as the bike accident he had back in August 2020 which saw him end up in hospital after breaking his back.
Following her act, Simon's fellow judge Amanda Holden said: "Oh my goodness me, every single one was a banger.
"You have got funny bones, there's nothing else to say.
"You've got it in your blood, you are naturally funny.
"Every single joke was a winner darling, and I looked at you and every single moment was funny. You are so refreshing, so genuine, you're incredible."
Eva's mother, Kelly Abley, 44, said it had been a big surprise but her daughter is already preparing for the final show.
"We are just in shock," she said.
"It's crazy, not what we expected.
"She thought she would do her act and was going home but she got through. She's not stopped smiling.
"To get the judges reactions, that was just the icing on the cake.
"She's just so happy she's managed to get her voice across to people. It's lovely to see that people love her for being her."
And she said Eva is already well prepared for the final on Sunday. "She's already written a script for the final and is ready to go out there and smash it again," Kelly added.
"She'll be practicing but we've got a busy few days ahead. She's going to be a bridesmaid on Saturday for her uncle.
"She doesn't have any time for nerves. We will be travelling up to London the next day."
Eva, who is home-schooled, had her first taste of stand-up comedy when she entered a talent competition on a camping holiday to Newquay.
Kelly added: "I think there's opportunities for her to do a lot of things in the future. "She's proved herself to a lot of people.
"The world is her oyster."
Singer Tom Ball was put straight through to the final after receiving the most audience votes on Wednesday night's show.
He blew the audience away with his powerful rendition of Conchita Wurst's Rise Like A Phoenix, receiving a standing ovation from the judges.
Eva went head-to-head with Japanese magician Keiichi Iwasaki but judges Amanda, David Walliams and Alesha Dixon all voted to put her through.