I LOVE Astrid. One of my favourite names. I don't think you could have Soleil with Winter, personally. Not keen on Cecily or Shiloh.
Other ideas. Winter and ...
Anais, Anwen, Arwen, Amberley, Amaya, Allegra, Athene, Avery, Aria, Aubrey
Bronte, Briar, Bronwyn
Celyn, Cherry, Calliope, Carys, Cerys, Camilla
Delphi, Danica, Demelza
Effie, Ember, Everly, Eirlys, Evana, Erin, Eden, Elora, Eilidh, Evadne
Fleur, Fern, Fabia, Fenella, Ffion
Giselle, Gaia, Gliona
Hazel, Harmony, Haven, Hera
Isadora, Isolde, Ingrid, Iona, Inez, Imelda, Ivana
Juniper, Jacinta, Jonquil, Jessamy, Josette
Kiki, Karensa, Keziah, Katrina
Lorelai, Lyric, Liara, Luana, Livia, Larissa, Liberty
Misty, Miranda, Merryn, Minerva, Maren
Nova, Nia, Nyah, Neve, Neriah, Neriza, Nerilly
Ondine, Ocean, Opal
Pippi, Posy, Persephone, Paloma, Pandora
Quinn
River, Raine, Raven, Raina, Robyn, Rhiannon, Rhiannyd, Rowan, Romilly, Rivkah, Ramona, Romy, Remi, Ravenna
Saffron, Sorrel, Saskia, Skye, Soraya, Sapphire, Stella, Samaris, Serenity, Seren
Taryn, Tansy, Tamsin, Tamara, Talitha, Tasmin, Tamika, Trinity
Verity, Vanessa, Viola, Vashti, Vita, Veda
Wren
Xanthe, Xenia
Ysanne, Ysabel, Yseult
Zeryn, Zola, Zia, Zillah, Zelda, Zinnia