A remarried spouse receives 1.5 times the statutory inheritance share regardless of when the assets were accumulated or whether they contributed, and directly reducing this is impossible under current law. The bigger issue is successive inheritance, where assets inherited by the stepmother upon the father's death pass intact to the stepmother's children after the stepmother dies.

If the stepmother has dementia, her child, as her adult guardian, may represent her in inheritance negotiations, creating a risk of conflicts of interest. While successive inheritance itself cannot be blocked, the key response is to adjust the actual distribution ratio through claims for a contribution portion and special benefits in the first inheritance, along with an in-kind partition strategy, and, if necessary, petition for the appointment of a special representative.

Source: Official blog of Attorney Yoon Ji-sang, Law Firm Jonjae / Click the blog link below to see more detailed information.