Or maybe it’s Minty’s sister (or her future husband’s sister).

Maybe this has something to do with Doctor Whooves/Time Turner?

that’s nothing. derpy once travelled back in time 5 times to ride on the ferris wheel.
 

@chris the lovable jerk 
I can’t believe someone still remember Codename: Kids Next Door.
 
Fountain of Youth? Nah!!!
 
Probably one of her Magic experiments gone wrong that sent her back in time. Personally, sounds more logical than a time machine in the shape of a police booth. 
And Dinky in Twilight’s filly school, I imagine she use the time spell again to jump back to the present but partially.

Y’all are acting like this is the first time Dinky (aka Background Unicorn Filly #2) has appeared in the past:  
>>929628t (merged)
 
@Background Pony #D130  
I can’t say I agree with that chart, but I appreciate the creativity and think it’s as good a headcanon as any.

Dinkiy Hooves shouldn’t be there

Either Dinky’s on an outing with Doc or she’s like that Leaky Leona girl from Kids Next Door

Twist: Turns out that’s Derpy’s mother.

@Dark Tail  
She also has darker outlines and a darker coat color than Dinky.

Must be Derpy’s mother, you’d be surprised how often grandchildren look so much like their grandfather or grandmother when they were young.

 
This is kinda how I imagined it.

@ChuymaruZ  
Wait what? I’m confused.

@Background Pony #D130  
OH MY GOD GUYS!

Maybe she’s actually Derpy’s mother? Given how much older she is than Applejack’s (future) parents and the coat color of that mare that is probably her mother, I can kinda see now how Dinky relates to Amethyst Star, though it follows the line that Derpy isn’t actually Dinky’s mother, but her aunt, and Golden Harvest and Written Script are Dinky’s parents. Amethyst is  
A: A cousin of Derpy and Written Script. That filly has a brother or sister taking more after their supposed mother, making him/her Derpy and Written Script’s uncle/aunt, and Amethyst Star is his/her child.  
B: Dinky’s aunt. Given how old that filly already is compared to the Apple’s parents, it is entirely possible that she had several children, Amethyst Star and Written Script being probably the oldest of the bunch, and Derpy being the youngest given that she is about the same age as Rarity, which means both Liza Doolots and Dinky (who are cousins) are old enough to be the CMCs age. I’d also like to remind you that she had more actual interaction with Golden Harvest and Written Script than Derpy and The Doctor, who she just sat next to.

@Mori  
Timy Whimy

Time travel

What is Dinky doing in the past?

@ChuymaruZ  
Seeing a familiar background pony in a scene that takes place in the past is the most exciting thing that has happened to me all day. I hope yours goes well too.

@Background Pony #5DB7  
@EPPony  
@Vree  
@northern haste
 
sigh…

@northern haste  
I’d say she’s most likely, along with Pinchy and Tootsie, is immortal or ageless.

Broke into you’re dad’s TARDIS again, eh little missy?

Dinky Hooves was around at least 100 years ago.

@northern haste  
Well her (adopted?) dad and mom are also.  
So she like, finds out and then they offer her to try it out.  
She only has to stand in line for an apple and it will trigger a chain of events that will ensure the prosperity of Apple Bloom and her family.  
It’s what Doc & Derpy do all the time.

Oh my god dinky is a time traveller