setting width to separate pictures in flatlist react native code example
Example: flatlist last item column 2
for your case use flex: 0.5 on the item container
therefore: Your item should have flex of 1/(number of columns) if you have 3 columns your item should have flex:1/3
///on flatlist
columnWrapperStyle={{
flex: 1,
justifyContent: 'space-evenly',
}