Taking to her Twitter page to share the happy news, the Countdown presenter revealed that she and her family would be donating £30,000 to children's charity trust, The Angus Lawson Memorial Trust.
WATCH: Rachel Riley's baby daughter makes her Countdown debut
"So thrilled to have won some money for @wwwalmtorg!" she tweeted. "Covid has been especially hard on charities and those they support, I know ALMT will make sure a lot of children will benefit from every penny from @FamilyFortunes. Thanks for the kind messages! Sorry about my bro's shirt."
Rachel, 34, also uploaded a sweet family snapshot with her husband Pasha and their baby daughter Maven, who turns one on 15 December.
Fans rushed to post underneath the post, with one saying: "Well done and a good cause to win for! Look at that little cheeky face between you very cute!" Another remarked: "You're an amazing woman with an amazing family… well done."
The Countdown star shared this new photo of Pasha and baby Maven
On the show, the couple were joined by the TV presenter's mother Celia and her brother Alex. They took on the family of footballing legend Chris Kamara.
The family's TV appearance comes shortly after Pasha made rare comments about little Maven during a chat on Lorraine, when he spoke about his experience of fatherhood. "I don't find it scary at all," he said when asked how he was feeling about his little girl turning one in December.
Rachel and her family on Family Fortunes
"I find it absolutely fantastic, I never knew what to expect. Being in this situation being a father, it's the best thing that could ever possibly happen to me. I am loving it."
On whether his daughter has already started dancing, Pasha added: "We're dancing a little bit already, she probably will dance before she can walk."
Make sure you never miss a story! Sign up to our newsletter to get all of our celebrity, royal and lifestyle news delivered directly to your inbox.