Route 753

Route 753 will clearly direct you from Silentstar to Clearbay. The area is quite grassy so there will be a lot of places to catch a lot of Pokemon. Oh, you should also put on some warm clothing. This area has a tendency to snow from time to time. It'll be hard to catch any Pokemon while you're wearing summer clothes. There are plenty of starter Pokemon to catch her. Ranging from Ralts, Abra, Swinub, Snorunt, Psyduck, Girafrig, Azurill and Sneazel.

Good luck, Pokemon Trainers.

Pokemon:
Ralts
Abra
Swinub
Snowrunt
Psyduck
Girafrig
Azurill
Sneasel