for the longest time, izzy wondered whether her brother would ever find happiness. true happiness, the kind that can only come when you accept who you really are. for her, it was incredibly easy to accept alec for precisely who he was. from her first hint at his sexuality to the night he announced his relationship with magnus, she accepted him, believed in him, and loved him. fiercely, protectively, loyally.
watching alec deal with his truth was painful for izzy. the sort of painful that left her scared, panicked every time someone came close to sniffing it out before he was ready. on more than one occasion, she did everything she could to throw people off: covering with their parents, diverting jace’s attention, demanding that clary keep the realization to herself. anything to keep him safe, to make him feel more secure, to protect alec from anyone who might threaten his place in the shadowhunter world.
jace, she sometimes feared, was a threat. she grew to love jace for his tenacity and dedication to training ( and, y’know, the fact he always wanted her to tag along on their super secret missions ), but he scared her, too. alec looked at jace the same way he looked at izzy’s posters of those mundie singers; the only difference was, jace was real. he was real and tangible and living under their same roof. she saw the intensity with which alec looked at him, the way he’d throw himself head-first into danger if it meant keeping jace alive. it terrified her, the thought that alec might feel something for him ---- terrified her even more, because she knew jace didn’t. in jace’s eyes, they were brothers. in alec’s, they were something different altogether.
enter magnus bane: the glittery, ostentatious warlock. maybe not the ideal partner for a shadowhunter, but someone who was fastidiously sure of himself ( and his sexuality ). from that first night at the loft, izzy saw a kinship there. magnus was someone who would understand, who wouldn’t judge alec or be a danger to his standing within the clave. ( and, hey, he was cute, and if she got to pilfer through his extensive collection of glitter and rouge, she wouldn’t be upset about that, either. ) she tried dropping hints ---- “i thought you might hit it off.” isabelle’s eye makeup glittered as bright as tears as she glanced over at her brother. “get to be friends.” ----- but alec was stubborn & resolute. so, she settled for letting him do things on his own time, though she was quick to drop little hints and comments along the way.
it goes without saying that izzy is unbelievably proud of who alec is today. she looks at him and sees everything thirteen-year-old izzy was terrified she wouldn’t: someone who is comfortable with who he is, what he wants, and how he lives his life. someone who has found a true, everlasting love, complete with the two adorable children she gets to call her nephews. looking at alec now, so beautifully happy and sure of himself, she feels nothing but peace. this is what she wanted for him, and she’s thankful every single day for the person her big brother has become.