Legal Question in Real Estate Law in California

Unfortunately, yes. When multiple owners of real property cannot agree whether to keep or sell the property, any of them can file an action for partition. In the old days, farms and other large plots of land were actually partitioned into separate lots. With modern subdivision laws that is not possible, and of course it cannot be done with a single-family dewelling. So the court will order the property sold and the proceeds divided, unless the parties make some other settlement.

I agree with Mr. McCormick. Partition suits are less common recently because so many properties have no net equity, and there's nothing left to distribute to the former owners after the sale. Although you can in theory be sued for partition and the property will be sold, there is no legal way to force a buy-out. A buy-out may, however, be exactly what you'll want to do if a partition suit is filed. You didn't mention whether the property has any loans against it, but if not it may be relatively easy for the two of you who want to keep the property to finance the buy-out of the other two 1/4 interests. This would avoid family wrangling, lawyer fees and a selling commission.