Is it made by mexicans?

Not sure where it was made. Purchased as a gift.

I don't know where it was made - there is no tag. But a very nice sombrero!! It came bent in the package but after 24 hours was perfectly shaped.

Does this indeed fit most adults? Some of the reviews say it does not.

No it's made to fit horses, LOL, just kidding, it looks to be a bigger medium size, it fit me basically ok and I have a fairly large head but the fit was just a little tight. I use mine in the summer while mowing to help keep me cool. The string built in helps keep my hat from blowing away. Hope this helps

Would this fit a 10 year old? Thanks.

Probably not, most kids heads are a bit smaller until they grow up fully, these hats don't seem to come but in one adult size, mine fit a bit tight but seems to work ok. There's a strap on it to hold it to you in wind. If the hat you get is too loose on your child's head and you cannot find a child's size hat, you might try putting a thick stocking cap on first but it may be a bit hot that way.