Caer got some of the house elves to help him out with this (who knew there were a bunch of sappy romantic house elves in Hogwarts?). Anya's bed was surrounded by a mixture of red and white hollyhock flowers that were enchanted to bloom in a wave like effect when she woke. One of the flowers bloomed and released a note onto the bed:
A little birdie told me these were your favorite. Happy Valentine's Day - See you at breakfast.
Caer and Anya had a private breakfast which Caer set up in one of the greenhouses full of flowers. After they had finished their food Caer gave Anya her real gift: A beautiful orchid necklace. He wanted to get her something small and modest but he couldn't stop himself from buying this one when he saw it. Hope she likes it!
For his other girls: Katja, Cel, Jana, Viktoriya, Elizaveta, Dex, Dani, Cielo:
A single white rose With a small note attached that says:
Congratulations. - Caer.
[OOC: Just in case you were wondering, it's a Russian custom to say congratulations to women on Valentine's Day, so Caer likely said this to all the girls he knows.]