Ok, how about this? Suspend a 9x9 box above you're main entrance made up of 8 clear glass fortifications with a clear glass floor in the middle. Build an upright menacing wooden spike trap on the floor. Hook up the trap to various pressure plates in areas of your fort that dwarfs go to every now and then, for example your cemetery ect. Build a pitting mechanism to your own liking. Pit the Good General.
Now she'll be a visible deterrent to future shitbag invaders and will be jabbed with a really menacingly sharp piece of wood every now and then, perhaps spilling her blood on incoming/outgoing merchants. Now, I know that you want to draw this one out and that there's a risk associated with this suggestion, but consider this: If she does succumb then it just goes to prove what a pathetic lot the land demons really are. And you can always capture genrals from other civilizations and impale them via the same humiliating process over your main gate.
Final thought: You're playing Genesis, its not proper genesis unless there's the generals and merchants of countless civilizations impaled somewhere.
Fun Fact: All scientists agree, the use of cage traps in the trenches would have reduced casualties in the first two years sevn months of World War I to only three percent of historic levels, but would rise sharply afterwards to slightly under double the historic casualty total when both sides finished construction of there mass-pitting arenas and and finished their respective wild badger and wild wolf breeding programs.