Sisters for your boy names: (I love these! 
)
Magnus Roland and Valeria Judith
Maximilian Remy and Cassiopeia Quinn
Cedric Dimitri and Rhiannon Sasha
August Caspian and Harriet Susan
Dylan Frederick and Bridget Louise
Arthur Endymion and Lena Gwendolyn
Ansel Peredur and Heidi Elowen
Gareth Florian and Isabel Hannelore
Edmund Ludwig and Wendy Harriet
Edward Amaury and Margaret Celeste
Cornelius Hart and Millicent Rose
Brothers for your girl names:
Cecily Beatrice and Damian Casper
Seraphina Thisbe and Endymion Leo
Aurora Eilonwy and Griffin Lysander
Charlotte Melusine and Edmund Larkspur
Felicity Bridget and Arthur Caspian
Cordelia Poem and Alexander Story
Matilda Rosabel and Edward Oliver
Rosalie Amoret and Emerson Jules