1832 - Why did Mary Ryan steal ammunition?

[Anneatki]

Hello there, I'm hoping someone has some idea why 22 year old Mary & a friend stole 60 rounds of ball cartridges from a soldier in the Templemore Barracks? 
In October 1832 at the Clonmel Assizes, both ladies got a sentence of seven years transportation.
They were found in the Barracks on "the Officers Stairs" with the ammunition - could it have been a prank gone wrong, or would they have been able to sell it?
I can't find any details of the Trial, just brief mentions in the Clonmel Herald, so any suggestions?
Thanks! Anne