I wouldn't call it spoilt. She's 16. She suddenly got whisked away to a different world without her friends and family. Knows no one. Can't go home and had a perfectly good life. In a situation when you're alone and scared it isn't odd to rely on the first hand that reaches out to you especially for someone so naive and young.
The Prince is actually limiting the people interacting with her. Forcing her to be more reliant on him. I really think her behavior is normal at this point.
I agree. I also don't think Aira fell for the prince. It's clear Aira could only trust him and rely on hum, being the one who dragged her into his world and there was likely no way back.
And I don't mean that in a negative way. I think she is just spoiled and super not used to doing much on her own as an only child. It is part of why she fell so easily to the stupid prince. Contrasted with the FL, who was a workaholic and is older, and it is not surprising how one managed to make her own way and the other just blindly relied on others.
Also, and more importantly, I think she is resentful. Like super resentful. She seemed to have a perfectly fine life before being summoned. Maybe even more than fine. Only to be dragged to a new world and told that she can't go home. She might feel that it is only proper that the Prince handle everything for her. And in some ways she is right. But no one should let others handle their business to such a degree.