Physic Gem: Book One in the Poke-Kids series

Lavender and Summer are twin sisters with an big secret, they can talk to Pokemon.
One day Team Rocket resurfaces again, and Lavender with Summer and two others have to stop Team Rocket from capturing the three legendary beasts. The four kids will find out a bigger secret than being able to understand Pokemon.
Will they be able to stop Team Rocket?
What is the secret bigger than understanding Pokemon?