They just like it on your shoulders so well they don't want to leave. That's not bratty

'Tiels are so small that I don't worry about their bites unless I need to catch one for vetting or medicating. Then they can panic and bite really hard, but just getting one off your shoulder shouldn't be too hard. My way is to gently but firmly put my finger to a foot while saying
Up in a calm and firm way, like I'm teaching, not reprimanding. If at first, she resists, maybe she'd let you cup her in both hands loosely and pick her up that way. Worth a try while she's learning. Try always to let her get her feet around something, finger, thumb, or another part of your hand. They don't like the insecurity of just dangling.
I give shoulder rides to many of my birds and have no qualms about 'tiels at all. Obviously, the larger the bird, the greater the lunge capacity and beak strength, so I'm selective. I like my eyes and lips as they are.