The two games will consist of one 35-minute half each, giving teams the opportunity to experience more styles of opponent across the three festival matchdays.
28 players have been selected for both matches, with a full 15 positional or personnel changes between the two starting teams.
Eve Mackay, who captained the side for their opening day draw with Italy, will lead the team for the first fixture against England.
Loosehead prop Ellen Nimmo will then take the reigns for the 2pm fixture against Ireland.
Scotland Women U18 team to face England at Wellington College today (kick off 12pm – live on YouTube
15. Neve Murray
14. Connie Sanderson
13. Robyn Allan
12. Lucy Symon
11. Bethan Mathieson
10. Lucy Ronald
9. Emma Wylie
1. Amy Vance
2. Emily Sansom
3. Lilly Clarkson
4. Anna Stoddart
5. Layla Mitchell
6. Eve Mackay – Captain
7. Juliet Ramsay
8. Estella Vaughan
Replacements
16. Gemma Gordon
17. Ellen Nimmo
18. Jess Combe
19. Megan Hutchinson
20. Rebecca Whitehead
21. Pip Sutherland
22. Eilidh Rose
23. Eleanor Keenan
24. Rhianna Bodle
25. Danielle Kaschula
26. Niamh Waters
27. Kat Bird
28. Megan Laurie
Scotland Women U18 team to face Ireland at Wellington College today (kick off 2pm – live on YouTube
15. Bethan Mathieson
14. Robyn Allan
13. Kat Bird
12. Niamh Waters
11. Megan Laurie
10. Sophie Gilvear
9. Aoife Powrie-Smith
1. Ellen Nimmo – Captain
2. Gemma Gordon
3. Megan Hutchinson
4. Rebecca Whitehead
5. Pip Sutherland
6. Rhianna Bodle
7. Eleanor Keenan
8. Danielle Kaschula
Replacements
16. Emily Sansom
17. Amy Vance
18. Jess Combe
19. Lilly Clarkson
20. Layla Mitchell
21. Neve Murray
22. Eilidh Rose
23. Eve Mackay
24. Estella Vaughan
25. Connie Sanderson
26. Emma Wylie
27. Lucy Ronald
28. Lucy Symon