
Please be aware that most good breeders will not sell pups for Christmas presents, neither will they sell them as a 'surprise' because they will want to meet all members of the family who will be involved wit the primary care of the dog.
Are you even sure that you grandma wants another dog at this time? You do not say how old your grandma is but as Westies can often make 15 years of age, will she still be able to cope with the demands of a dog as years go by?
It might be a better idea to give your Grandma a card for christmas with an IOU inside for a Westie pup, that way, if she definately wants one, she can be involved in the search and choose her own little companion.
*edited* SNAP!! posted at the same time as Jeangenie