Rochelle owns a number of Donpan and she trains then to sniff out amberite so she can sell it so that it can eventually be turned into jewelry.
Amongst Rochelle's Donphan there is a young Donphan which can be identified with it short tusks. The young Donphan was currently being trained by Rochelle to sniff out sources of amberite efficiently.
After Team Rocket steal her Donphan Rochelle manages to track them down with the help of her other Donphan and Ash.
Once the Donphan was recovered Rochelle has Pokemon battle with Ash Ketchum where she defeats Ash's Heracross using one of her Donphan