Awesome to hear that! Congratulations to you both!
I have tried to find out what happened in Arda or on Earth (related to Tolkien) on December 15, but I could not find anything.
Still, I thought about what her name would be in Sindarin.
Annika would be a Scandinavian form of the Hebraic Anna, the "Gifted", which translated would be more or less Antael.
But, the name may also come from Greek nike as in victory, and with the prefix would mean so much as "Unconquerable". Translated it would Alorthora or something similar.
Whatever it is, both would be nice names!