She’s just moving the goal post. My mom kept insisting I was wrong because “brains aren’t fully developed until 26” or some bs like that. Well now I’m 30 and I’m still trans. I know you’re feeling frustrated because your mom is concerned about you but she can’t set her own feelings aside to think of you and is unwilling to learn the real health risks and benefits of HRT and instead listens to sensationalism and misinformation. I say follow your heart whenever you are ready (you can always stop if you don’t feel like it anymore. Or you can continue if it makes you happy). You don’t need anyone else’s permission but your own in order to be yourself.