If you've managed to be teleported to the Beastial Sanctum at some point earlier in the game, you can also fast travel to that Site of Grace and go south to reach the church.
Which is sad since the game have my favorite NPCs in the series.
Immediately hop on Torrent and take these smaller enemies out while dodging O'Neil's attacks.
Reload the area, and Millicent will move, and Gowry will return.
Give her the needle and then rest at the nearby Site of Grace to reset her dialogue.