She ain't there because she has to call you 10 times first.
Behind the Pokemon Centre in Nimbasa City (like 2 tiles from the lampost on the left)
Near the Officer in Route 16
Behind the fence on the bottom of Route 5
Somewhere near the slope to Clay Road in Driftveil City
Across the first bridge and near the ledges of Route 6
Around the stairs near the Breeder in Route 7
On the Airstrip of Mistralton City
Route 9 near the Hidden Hollow
Yamaji Town near the stairs.
Undella Town between 2 rocks
Route 13 near the start from Undella Town which is behind the ledge. Somewhere around there. There's rocks and a Fisherman.