Croesyceiliog teammates, Kerry Jenkins and Rhian Wilmott take the half back positions, with Scrum Half, Cath Walkley returning from the 'A' squad to take a place on the bench. Fly half, Awen Thomas is also on the bench following her performance against the French.
Dee Croft earns her first cap replacing Jamie Kift as hooker, following a knee injury earlier in the week.
Props, Dawn Mason and Kath Lenaghan will be under pressure to perform as Amy Broadstock, who received her first cap a fortnight ago, will be eager to play a part in the game.
Louise Rickard, who stars in the BBC2 documentary, 'SAS - Are you tough enough?' on Sunday night, plays at outside centre with Claire Flowers and Sue Jones on the Wings. Naomi Thomas, who has won 'man of the match' in the last two internationals, plays at full back.
National Manager, Gareth Kear commented, "After our first two games, where we won one, lost one, we feel that we have to pull together all the positives from both previous games. We know we have the ability to beat Spain and although it will be a difficult challenge playing in Madrid, if we can stay focused and play to our strengths, it is a game that we can win."
The Game kicks off at 12.30pm on Sunday at the Spanish National ground in Madrid.
1 DAWN MASON 2 JAMIE KIFT 3 KATH LENAGHAN 4 SUE GRAINGER 5 LIZA BURGESS 6 KYLIE WILSON 7 PIP MINTO 8 APRIL DENT 9 KERRY JENKINS 10 RHIAN WILMOTT 11 SUE JONES 12 MELISSA BERRY (CAPT) 13 LOUISE RICKARD 14 CLAIRE FLOWERS 15 NAOMI THOMAS
16 AMY BRAODSTOCK 17 CATRIN EDWARDS 18 JACKIE MORGAN 19 HELEN EDWARDS 20 AWEN THOMAS 21 CATH WALKLEY 22 KAREN MAYZE
Nearly 40 players were involved in the first Wales Under 18 training session of the season. WRU National Performance Manager Gethin Watts is excited at the potential shown by the group and expects the Regional Under 18 Championship to hone their skills even further.