The 22-year-old is in intense training for the Olympic trials in Birmingham in June, which is set to be the make or break moment as she attempts to jump the 1.95m A standard.
Lassu trains with fellow high jumpers Emma Perkins and Isobel Pooley under British coach Fayyaz Ahmed with all three looking to secure one of potentially three Olympic spots available.
Former England under-23 champion Lassu faces a tough ask with her personal best currently standing at 1.83m - but she claims she is ready to tackle the pressure cooker in the Alexander Stadium.
"I feel as if I am in the best shape of my life and it is now just about going out there, doing it and letting myself do it," said Lassu.
"The arena is pretty huge so the atmosphere at the trials should be incredible. It is going to be the biggest competition I have ever competed in.
"If you put too much pressure on yourself you won't perform so you have to accept that not everyone is going to qualify but if you have done the work then at least you have created the opportunity.
"Quite a few girls will be battling it out but Isobel and Emma train with me so the ideal scenario is all of us qualify as the three.
"I think it is going to be really good practice to jump at the Olympic trials with the home crowd and it could be an amazing competition.
"We are battling for a place on the team just like you have to battle for a place in the final or a medal at the Olympics."
No matter what happens Lassu is guaranteed to play one part in this summer's Olympics after being chosen to carry the London 2012 Torch courtesy of Lloyds TSB.
But Lassu, who will run with the Flame through West Bromwich on June 30, admits she isn't thinking about it just yet with the chance to compete still alive.
"The week before the Torch Relay come the Olympic trials and it would be easy to get whipped up in the excitement and take my eye off the trials," she added.
"Since I was at primary school I have always been fascinated with the historical aspect of the Olympics, so I am over the moon to be part of the Relay.
"But the Torch Relay is set in stone, me going to the Olympics isn't, so I want representing my country in the Relay to be the icing on the cake of competing at the Games."
As the only National Presenting Partner of the London 2012 Olympic Torch Relay, Lloyds TSB is bringing the excitement of the Games and Olympic Flame closer to you. Find out what we're doing in your community and who is carrying the Flame at lloydstsb.com/carrytheflame