Offspring is a substitute, but it somehow seems awkward to use that word, too.
It is too impersonal. No humor intended, but the word or phrase used probably depends on how close one is to one's children. My mom still calls my sister and I her kids, while my maternal grandmother refers to her next of kin as young'n's. Personal choice is probably the best answer to this query. Valhalla is not a synonym for Heaven unless you happen to be a Viking.