Stormy is extremely cuddly. Icy and Darcy are NOT.
I did indeed have that in mind
Crying
Icy: Doesn't cry. How dare you assume that. That's...ridiculous
Darcy: We actually see her cry in the show, and I believe that she would be a full blown ugly cryer. Hot mess. Completely smudging her makeup, mascara running down her face. Think that one picture of Kim Kardashian. She doesn't cry that often or that easily though.
Stormy: She tries to cover her face, with her hands or by turning away from her sisters. She is embarrassed that she is crying and as the youngest it worried she will be seen as less than or a crybaby. She also kicks thinks and hits things.
The trix do NOT share clothes with each other. For one, their styles are different enough that they don't really have any desire to. They actually respect each others belongings and don't go through each others things. They do really trust each other. If they did want to borrow something they would ask the other sister first and let them be the one to grab it. They may be evil and competitive, but they respect each other's space (side eye to my sister)
Their mother would always be very open about who was her favorite child at any point in time. It was usually Darcy (because she was a suck up) or Stormy (by default). It was almost never Icy because she was more likely to be blamed for her sister's behavior.
This led to them being so vulnerable to Valtor pinning them against each other later on.
In this one too, she just looks disappointed
I find this photo of the trix so funny
Icy and Stormy are putting effort into posing, meanwhile Darcy is just holding out her arm
I keep imagining they were told to pose with the gloomix and Darcy just raises her arm slightly all "what more do you want from me?"
No effort was put in on her part and I think that's beautiful
Birthdays:
(Note: in my mind the trix are sisters, but not triplets. I'm sorry there is no way Stormy and Icy are the same age)
Icy: December 13th - Idk she just definitely has a December birthday and 13 felt right. She was not born on a Friday the 13th, but she lies and says she was. No one is going back and doing the math anyway
Darcy: October 4th - She definitely felt like an October Libra to me, so here we are. No reason for the 4, I just felt like it should be an even number for her. she is born ten months after Icy and for the short time they have the same age they have a lot of tension between them
Stormy: May 5th - Despite being my favorite trix (and winx character) and the one I have the most headcanons for I have very few opinions on when Stormy's birthday should be. May 5th is the date listed for all of them in the wiki and the date just felt so wrong for Icy and Darcy so she got to keep it. She is about 19 months younger than Darcy if I am doing the math right. (Because she is clearly the youngest and I will fight anyone on this)
Broken bones because I also realized I have opinions on this
Icy: Has never broken a bone in her life. She is terrified that one day she will, but would never admit this out loud. She doesn't admit any of her fears out loud and makes you feel inferior if you do.
Darcy: In the cinelume dub (I think) she breaks her nose when the trix are trying to summon the power from Stella's ring. It gets fixed immediately when they do that reverse spell. Maybe she would have also broken a finger at some point. I can't really picture it breaking any major limbs. (In the comics she breaks her leg, but I don't feel like counting that today)
Stormy: She has probably broken her arm as a kid at some point and it was probably Icy and/or Darcy's fault, but they would deny it
Heights:
Icy: 5'4/162.5cm : She just seems average height to me. Of course she appears taller because of the hair and the heels
Darcy: 5'7/170cm : This one was hard because I imagine her as quite tall, but I don't imagine riven as super tall and there is no way season one Riven would date someone who isn't at least a couple inches shorter than him. He has too big of an ego.
Stormy: 5'0/ 152cm: Stormy is small. I just love the idea of her being short and angry. It's just too funny. If she is not the shortest in the reboot I will scream.
Greatest fears (or one of them)
Icy: Her greatest fear is loss of power. She can deal with failure and rejection (she is used to it by now), but she would not be able to cope with loss of power. Not only her magic powers, but the power she has over others. She needs her sisters to be looking up to her. She needs to be the leader.
Darcy: Darcy would be most scared of loss of control. Darcy is a strategist and plans everything out beforehand. She is very conscious of everything she does and not having control would be stressful and demeaning for her
Stormy: Stormy would be most scared of getting left behind. She is scared of her sisters abandoning her because they see her as stupid and impulsive. She is scared to do things by herself and figure out how to live independently. She has major FOMO
It just seems kind of random