The 21-year-old will compete alongside Jenna Randall in the duet.
"Every competition is a stepping stone towards the Olympics," said Allison.
"The Euro Cup will be a great opportunity for us to experience the distractions we're likely to face with a home crowd in London."
Great Britain will also field a 10-strong combination team in Sheffield, and they go into the event with their new 2011 routine, which has already brought them success this year.
"It's themed to dolls," said GB's Lauren Smith.
"We performed it in Germany [in March] where we got a bronze medal, so we're really looking forward to bringing that to Sheffield to show what we can do."
The crowd will also be treated to displays by some of the world's best, with Olympic champions Russia and Olympic silver medallists Spain both set to compete.
Russia have dominated major international synchro competitions in recent years, having won the team and duet titles at the past three Olympic Games and the past four World Championships.
"Europe is definitely the strongest area for synchronised swimming in the world," said GB synchro high performance manager Adele Carlsen.
"In addition to the likes of Russia and Spain, we've also got Italy and Ukraine who are in the top five or six in the world.
"The duet beat Italy [in Germany], so to be up against them in Sheffield will be really exciting and with the home crowd behind us I hope we can pull up another spot or two," Carlsen told BBC Sport.
In March Great Britain's synchronised swimmers learned that they would be guarenteed host-nation places in both the duet and team events at the 2012 Olympics.
Since then the competitors have continued with their rigorous training regime - roughly 42 hours per week - in preparation for this year's events.
While the Champions Cup is a key date in their calendar, the World Championships in Shanghai in July is GB's main focus for 2011.
"In many ways the World Championships are more difficult than an Olympics because you have representation from so many nations," said national performance director Biz Price.
"Realistically we would view success as having the duet placed within the top 10 and the team within the top 12 nations as they [the World Championships] will be one of the last major international meets before the Olympics."