Try to comfort your cat in any case give lots of attention and continue to play with her. Often, a cat whose owner has died must move to another home and begin to adjust to another owner and new surroundings. Cats are not always good at moving, but it's possible that a cat will forget the object of its grieving in a new home. A cat who is adopted into a new family after his owner's death may find himself in a household with other cats. This is especially hard on an older cat.
Support groups are a very good way to help with dealing with grief.
Thankfully, there are many out there and available. Veterinary Medical program is a large site with very helpful information for anyone dealing with this type of situation. Finally, there are many feelings on whether or not people should get a new cat after the loss of a family pet. It really is up to the family to decide. You can never replace the cat that was lost nor should you try.