How should this nickname for Adelaide be spelled? [closed]

Say you're writing a book, and a character calls another character this nickname for Adelaide. How should it be spelled?

• Lady
• Laidy
• Laidey
• Laidie

Addelaide is an old name, so wondering if there's a historical way it was spelled or even just instances of any 1800s spellings of it. My own research has found no consensus amongst modern usage and cannot find old text containing the nickname.

Solution 1:

In Google Books, I can find Rose Gurney's Discovery, by Mrs. G.S. Reaney, written in 1880. One of the characters is named Adelaide, and goes by Laidey:

And Adelaide, more generally called "Laidey," yawned languidly.

This doesn't mean that "Laidey" was the only way to spell that abbreviation for Adelaide. It would be almost impossible to search for an abbreviation of Adelaide spelled "Lady," and there could easily have been other spellings which I was unable to find. But "Laidey" is certainly an authentic way to spell it.