“Acting like a spoiled brat” is what they’re doing literally when someone is 撒嬌ing, but it doesn’t communicate the idea that it’s supposed to be cute and endearing lol. And pamper... it’s a little like 拍馬屁 (but with the same intention as 撒嬌) so it just doesn’t feel the same... I can define it as “acting cute to gain a favor” but it’s not a phrase I’d use lol