FAW officials say they have been told Wales are expected to have more fans in Switzerland than all bar three other nations taking part in the 16-team tournament.
Isabelle, 12, from the Rhondda is very excited and “can’t wait to watch the match”.
Along with her dad Leon, 44, they have never been abroad to watch them but have been to every single home game.
She said it was “massive for women’s football”, and had a score prediction of Wales winning 3-1.
Many of the travelling supporters have congregated at the city’s fan zone, where tournament organisers, Uefa, have arranged live music and activities to add to the celebratory feel.
Olivia, 16, is in Switzerland with her dad Lyndon and mum Nichola. She said her family were there “to support them, to encourage them and to make them feel more motivated to do well in the tournament”.
Olivia, who plays football, believes Wales’ involvement in the tournament will have an impact on domestic football.
“It will encourage people to play, to come and support them and watch the game,” she added.
“The Welsh girls have made history just getting to the Euros,” said Nichola, 52, from Cwmparc near Treorchy.