All the modern AUs I could think of were done by you, so this list is mostly canon time, sorry! I also have a strong penchant for porn that will show through though I've tried not to include all PWPs. Some were taken directly from fitz_y's A Fic Rec Extravaganza Eleganza and from a previous list of Freya-related recs I did for camelot_fleet

Craft:
There's a Merlin group of cosplayers that had a lovely Freya - Freya's cold - and did some Merlin/Freya h/c fluff - Here, use my jacket, Freya and Freya and Merlin hug (all G and SFW).

Art:
Moonlit Floor by altocello (Freya/Merlin, G)
Merlin- The Lady and the Witch by quinmari (Freya and Morgana, G)
Untitled by anon (Freya/Excalibur, mature - NSFW)
One Day, Merlin, I will repay you” by travellingskyward
Top Ten episode - lady of the lake (Merlin/Freya, canon) and untitled (freya/Merlin, modern AU) by amness

Vid:
Love Story by valika56 (Merlin/Freya)

Fic:
Lightshow by meri_sefket (Freya/Merlin)
A Gift Unasked by vanessarama (Arthur/Merlin, Freya/Merlin, Arthur/Merlin/Freya with Merlin as branch) I remember loving this to bits for all the Freya POV it offers and how Freya she felt, despite how little we got the chance to see her in the show.
Help a Girl Out? by cat_77 (Freya/Vivian)
Blackbird by isabear (Freya/Morgana)
These are the Fables by ? (Freya/Nimueh, Freya/Vivian)
Beneath the Starlit Sky by anon (Freya/Elena)
The Waters of Avalon by anon (Freya/Merlin)