Both Williamson and her Arsenal and England teammate Beth Mead ruptured their ACLs in the last WSL season, and have since been out of action for club and country.
But as Mead made her long-awaited return to Arsenal action against Aston Villa last weekend, she told the Evening Standard about a special gift from Williamson which had helped her through the difficult time.
She said: "Leah bought a karaoke machine for my birthday.
"I think the day we got it, me and (Arsenal captain) Kim Little were singing a Backstreet Boys number."
And ahead of Arsenal's next match against Bristol City on Sunday, manager Eidevall was asked what he thought about the new addition to the Arsenal squad.
He remarked: "I've been seeing the karaoke machine carried round the training ground.
"I think it's found its place now - it tried to come into the medical room a couple of times and they have been playing some really strong defence in the medical team trying to get that out so it doesn't disturb the treatments.
"But we get to spread the joy in other rooms in the building. It's been good to see some good dynamics in the group."
Arsenal had an unconvincing start to the new WSL campaign, losing their opener 1-0 to Liverpool in front of a record league crowd at the Emirates.
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But after salvaging a 2-2 draw against Manchester United, they picked up their first win of the season as they came back to beat Aston Villa 2-1.
And it was Mead who came off the bench in the 88th minute to provide the assist for the winning goal to fellow Lioness and new Gunner Alessia Russo.
It was her first appearance in almost a year, after she spent a difficult period sidelined for the Women's World Cup in Australia and New Zealand.
Williamson also missed the summer tournament after rupturing her ACL in April 2022 - along with Arsenal teammates Vivianne Miedema and Laura Wienrother who added to the club's injury woes.
But Williamson has been trying to find ways to keep her teammates spirits high during their recovery - and the karaoke machine was the perfect idea.
Eidevall praised Williamson for the sentiment behind the gift and her support of Mead, saying that her ability to sense the needs of the time was reflective of her leadership qualities.
He stated: "To understand that sometimes you need a spark in something, and if things stay the same, it might just spiral down.
"You need to start with a laugh, for example, to start off a fire of emotions - you're right.
"That's why Leah Williamson is a great leader."
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When asked if he had tried out the popular new addition to the training room, Eidevall laughed as he declared: "I have definitely not had a go!"
But the Arsenal boss later admitted that if he is ever pushed to take a turn on the machine, he would probably settle for a Johnny Cash song.