Bullies? I mean, your right about diamond tiara because she DOES bullies ponies for not having cutie marks, but for starlight Glimmer, it’s not the same. Starlight wants to have friends that have equal cutie marks, so she removes ponies cutie marks and replaces them with equal cutie marks that have no speical talents.

They might be related.

@Crystal Neighybánya  
Silver Spoon just settles for stealing her milkshake.

@Scrounge  
I’m sure everypony - even Silver Spoon - wants to smack Diamond on occasion. It’s only natural.

@Crystal Neighybánya  
Agreed. As much as I want to smack Diamond sometimes, Glimmer’s on a whole other level.

Both Di and Starlight are smug and often unpleasant, but that’s about where the similarities end. One is just a pain in the ass, while the other is an equine Pol Pot.

@Background is Best Pony  

 
No. Resemblance.
 
But in all seriousness…
 

 
Mrs. Cake doesn’t have blue eyes.
 
 
So like I keep saying, family resemblance is a sometimes thing in Equestria.

@Scrounge  
Pumpkin got blue eyes. :P

@Vox  
Twi and her brother don’t look related, the twins resemble their father somewhat but don’t seem to have gotten anything from their mother at all, and the sheer number of relatives Applejack has means you could find an example going whichever way you wanted.
 
I’d say it’s there maybe about half the time, which is not really enough to call standard IMO. There’s certainly obvious cases of it (Rarity and Sweetie Belle look particularly alike, and Flim and Flam are essentially identical), but there’s also plenty of cases where you’d have never in a million years guessed they were related (Was anyone expecting Hayseed Turnip Truck to show up at the Apple Family reunion?).

Headcanon accepted.
 
@Scrounge  
The Cakes? Applejack’s family? Twi’s family? Rainbow Dash’s family? RD’s dad/brother/whatever looks almost exactly like her, and Twi’s her mother’s clone with a palette swap. Not to mention her brother’s cutie mark including some of the same elements.
 
You could cite Pinkie’s family as an example to the contrary, yes, but consider that hers was designed specifically to contrast against her - basically every family we’ve seen otherwise has had very strong resemblances within it.

Seriously though, people. Family resemblance is not standard in Equestria.

@Dr Outback  
4th? I only know of two others that where thought to be her mother and one was also thought to be here sister.

This is like Diamond’s 4th mother. I like to stick with my headcanon that Diamond Tiara has had multiple mothers

this is dumb

You want a headcanon? You want a headcanon? Here’s two. First: Glimmer is Tiara’s mother. Second: Glimmer is a Future version of Tiara that went back in time. Why did she go back in time? I dunno.

Narrator: “Unknown to Diamond Tiara, this is her older sister, Starlight, who ran away from home years ago.”

so you saying she is the john connor from the future WOW

@NostalgiaSchmaltz  
Which is hilarious given that the actual blood relations often don’t share a color scheme. Shining Armor looks more like Vinyl Scratch than Twilight Sparkle, and the Cake twins resemble their father but not their mother.

Actually, I’d LOVE to see a scene between DT and Starlight Glimmer.
 
“Wait…you want me to give up MY cutie mark…just so I can be no different from a…from a BLANK FLANK?!?!”

lol everytime a new character that’s mean is shown people believe that’s her mom, ah I love this fandom.

@Prof.NightJack  
or that evil runs in the family.
 
“this is your great grandmother Glitter. She won a beauty contest by spiking the other contestants drinking water and setting the manes on fire.”

@Background Pony #DD26  
OP did, “apple doesn’t fall far from the tree” is a term that means the child is a lot like the parent..

@Prof.NightJack  
who says Glimmer is the mother?
 
she could be an aunt or something.

I think OP is looking a bit too deep into things.  
No offense.