RE: PSE Spyder V4 youth bow. Maximun Arrow weight
I wouldn't be to concernd with a max arrow wieght. I would choose a shaft spined properly for your bow, with the broadhead of choice and tune it as well as you can. You could probably shoot 1000 grn arrows, but accuracy and trajectory would be terrible!
TAKE YOUR KIDS HUNTING AND YOU WON'T BE HUNTING FOR YOUR KIDS