Granny wanted to find her traveling bonnet, before the family left to find the connection of Pinkie's heritage. What was so important of this bonnet that she would even be angered by her granddaughters confusion of the flower strewn bonnet a top her head. Does this simple piece of head gear hold so much importance to the mare or was there another meaning for this simple piece of cloth.

A/N
If you haven't seen Pinkie Apple Pie yet, be warned that this contains spoilers.