That's a great twist on the vampire mythos, mirroring the goddess's giving up her immortality for love. Really like the universe building in this story
Heavy would be her half-human child not inheriting that immortality and dying before her. If that’s the case, losing her immortality would be a blessing.
Is the dream about if she kills/drinks blood from her own child, she regains her immortality? Damn...
Still, the mix of fantastical beings, motherhood/parenthood and identity questioning is really well done