Can the grown children of their deceased father force his widow to vacate her house that they inherited?

If the Will has not been admitted to probate yet, then there is no one who is legally entitled to represent the estate, and no, the deceased person's grown children cannot just go in and out of his property at will (assuming that the decedent was actually the sole owner of the house and that there are no surviving joint owners). The Executor will be able to do that once the Will has been admitted to probate, however.   A surviving spouse does not automatically have any right with regard to a house that was owned by a deceased spouse. However, if the deceased person was a Georgia resident, then his surviving spouse has the right to make a claim for something called "year's support." Under a year's support petition, the surviving spouse can request that the probate court award specifically requested assets to her as part of her year's support claim. The year's support award is taken off the top of an estate, before anything can be used to pay the decedent's debts and before the beneficiaries under the decedent's Will get anything. The year's support is a right under Georgia law; the decedent's other heirs cannot prevent the surviving spouse from seeking the year's support or challenge her right to it. They can only try to claim that she is asking for more than would be reasonably necessary for her support for one year, given her other income and other assets.   If the surviving spouse wants to know more about her rights, she needs to find an experience probate attorney, preferably one (in this case) with estate litigation experience, because it sounds like the kids plan to fight her on everything. She must not wait; she needs to act as quickly as possible. Otherwise, yes, should could face eviction.