Von Pinn/Mad

Collected speculations from various commenters:

Age and Construction
With respect to her time of construction, Von Pinn is perhaps 19 or 20. Agatha is nominally 18 years old, and Agatha was born no earlier than 407 days after Klaus Barry, though Lucrezia was presumably pregnant with her at the time of the Attack on Castle Heterodyne. Von Pinn may have been constructed more for Agatha than Klaus Barry, but at any rate early enough that she was known as the nursemaid for the latter.

It is not known, of course, the age of the materials used by Lucrezia when constructing Von Pinn. Theo would not have recognized them if they had belonged to his mother, supposing they become available due to her dying in childbirth. (Leave Theo with his father, Lucrezia may have thought, and put the remains to good use. Of course, the elder Du Medd would have willingly turned his young, motherless son over to Wulfenbach to get on with his research. Ironic if, unknown to all, the result was that a construct based on his mother actually took care of him.)

Mental State
"MINE!" — While that can be taken many ways, note that it isn't necessarily a threat, and note additionally that her immediate reaction is to tell Klaus the girl is hers — which could be taken as claiming the right to kill her, but could conversely be taken as saying that she won't let Klaus kill her.

Was she even really crazy at all, or did she witness something those around her considered impossible? I.e., if her prime directive was the protection of Klaus Barry, is she now so filled with antipathy for the personality currently known as Lucrezia that it spills over onto the Holy Child as well?

Or perhaps, has she been imprinted with the duty of caring for "the Heterodyne heir" (or "Lady Lucrezia´s heir") rather than Klaus Barry specifically, and "MINE!" means she comes to understand that caring for Agatha is her duty, which she cannot fulfill if Punch and Judy take Agatha off the Castle?

Eye
Her monocle: It covers what is either a mechanically or biologically altered left eye seen. Whether its use is for visual correction (unlikely) or cosmetic purposes is as yet unknown.

Interestingly, perhaps, Judy's left eye is also much different than her right, at least when last seen. (Most recently, that eye was bandaged over.)

Relationship to Castle Heterodyne
De end uff volume VIII: interestink torn uf events, yah? Zo mine qvestion iz, iz Von Pinn in direct contact mit der Kestle AI?

She iz not qvite hooman, und bilt in der Kestle (ve tink)... Could she be able to talk to it? Can it zignal her?

Was her insanity partially due to the Castle's sudden decoherence as well?