I have twice had my ATM card "scimmed" I think they call it in Nicaragua and Mexico and thousands taken and it took over a month to get my money back in both cases. I no longer trust ATMs in Central America.
I really had high hopes for Xoom but they are a no-go

So,
I think I am back to giving my sister my ATM card and having here western union me the money as needed. Luckily to that area of the world it is only $10 to send $1000 so doesn't break the bank, the biggest obstacle is to get my sister to get off her butt and go to the western union!!