mmm.. that looks very soothing.

In time, her pet will become a diamond.

It’s like those Zen meditation balls…

Boulder is really the rock she uses to sharpen her hooves for rock pulverizing.

I could watch her do that all day.

@ExtraDan ✿  
Don’t take my descriptions seriously. :p

@Dreamsicle  
awww I’d forgotten about that guy! But yes, I think that’d be the rock spirit she’d want.

@BunnyCat  
This guy?  

My headcanon is that, aside from her younger sisters, Maud didn’t have any friends growing up. So she adopted herself a pet rock and named it Boulder. She even began to give it a personality and refer to it as a male. Even as a full-grown mare, she still views Boulder as a beloved companion, as seen by her endearing habit of “sharing” her sandwich with him.
 
On a darker note, I imagine that if Boulder is ever misplaced, and not found immediately, Maud completely freaks out, to almost Pinkamena levels of creepiness!

Yes, because pulling a rock out of your wallet and polishing it against her hoof, is a term of taking care of her rocks.

she looks like she’s trying to summon the great rock spirit

Thanks, Sad Pony :D

She uses it to keep her hooves smoothed out and strong.