Pokemon Drives Me Nuts

Got my sister hooked on Pokemon… now I am trying to help her get all the types. Problem is that some of them are on different games and trying to get them to the higher games is… Not easy. In fact, my boys have allowed me to play their games to catch the ones she is missing… but one little problem. They never made their pokemon very strong nor did they go fight people to get money. So I can’t buy many pokemon balls NOR fight the really strong pokemon to catch them. Argh. I need a new hobby.