The Inbetweeners star, 33, made the discovery as she explored her showbiz genes on the latest episode of Who Do You Think You Are?
Emily comes from a long line of larger-than-life entertainers, with The Beatles legend Sir Paul McCartney her first cousin twice removed.
During her journey to discover more about where she came from on the BBC One show this evening, Emily headed to Wrexham to find out more about her family's love of football and her great-grandfather Ted Robbins and how he supported football in Wales.
The Celebrity Juice star learned how her late relative played a greater part in Welsh football than she had originally anticipated, and that he was considered a hero to Welsh football fans.
Ted Robbins, one of Emily's relatives, was Secretary of the Welsh Football Association and was heavily involved in supporting football across all of Wales for 30 years . As well as managing admin and general operations, he was also in charge of choosing players for the national team as well as being rooted at Wrexham AFC. Upon his death he was mourned by Wales, with headlines in papers at the time stating "Wales loses Ted Robbins".
Buried at Wrexham Cemetery, she visits Ted's grave to pay her respects to her football legend relative.
In her episode of BBC's Who Do You Think You Are? Emily visits Wrexham AFC football grounds to discover more about Ted and his influence on Welsh football and its history as well as understanding her family's love for the Welsh club.
Wrexham AFC was also Emily's beloved grandfather Mike's favourite team as she shares: "It just makes me understand now, my grandad Mike was obsessed with watching Wrexham - it was everything to him. I just never knew the real reasons why. I'm so proud, so unbelievably proud."
Ryan Reynolds and Rob McElhenney bought Wrexham AFC for £2million in November 2020, following a poll among the club’s 2,000 Supporters’ Trust members who voted overwhelmingly in favour of the two Hollywood stars becoming owners of their club.
Wrexham secured promotion back into the Football League earlier this year, with Ryan and Rob there to witness the club's achievement after 15-years away from the league in April.
"I’m not sure I can actually process what happened tonight, I’m still a little speechless," Ryan told reporters after the game.
"One thing that’s running through my head over and over again was at the beginning, people said ‘Why Wrexham, why Wrexham’; this is exactly why Wrexham, what’s happening right now, is why."
*Who Do You Think You Are? is available to stream now on BBC iPlayer