Never had to deal with it either. But increased excercise, both physical and mental, is the recommended treatment. Distract her with games and obedience training or nosework. There are medical treatments that the vet can give to stop lactation. It is important to not let the dog keep toys as "puppies" or lick their teats excessively as it will stimulate milk production. If it does not pass then veterinary treatment can be necessary in some cases. One also have to be aware that the risk for pyometra is higher in bitches with pseudopregnancies. Hopefully it will pass soon, I think it usually does, but I'm sure someone with experience will share theirs soon. And if in dubt, call vet for advise.