digging shihtzu

Question
i recently moved into a property with a back yard. i have a 10 year old shihtzu. She comes inside at night while we are up (2 adults 2 young children). This is a new arrangement it did use to be the dog and myself only. She has started digging in the yard during the day. she has a garage for shelter and the back yard to play. digging has not been an issue before. she gets walked reguarly and only seems to do this when we are not around so only during the week not week ends. any help would be greatly appreciated

Answer
A lot of other people would like such a answer too.  I don't have one, and in almost 8 years on dog Q&A sites I have yet to see anything that sounds good.  (The 3 hour walk every day might work, but do you have time for it?)  I have also never seen anybody post back that they tried this or that and it worked.  Later today I will be going out with a rake trying to fill the worst of the holes so I can mow.  You could put the dog in a doggy day care.  

I do have the fence lined with flagstone to keep the dog from digging out.  Good luck. Post back if you find anything that works.