poison is more dignified because 1 it doesnt alter the appearance of the animal
and 2 you can look her in the eye, stroke her head and scratch her behind the ear while administering it
as for a cremation vs burial
when speaking of humans, i prefer burial over cremation on religious reasons which i will not bring in here
but as for animals, i can see a few "reasons" why it may be better
the main reason would be that after a cremation you know she wont be cold out there and there will be bug bothering her
