Surroundings filled with rich girls with 〜だらけ
Grammar Explanation: Covered in with 〜だらけ

Chiya says it must be boring attending an elite school simply because they’re covering one’s tuition.
- 千夜:
- 「私
( だったら周( りがお嬢様( だらけで気( を遣( って疲( れちゃう」- “If it were me, I'd get tired of surroundings filled with rich girls and having to act proper.”
Key Points
お嬢様
( だらけ means filled with rich girlsだらけ attaches to the noun before it and says the surroundings are covered or full of that thing.
気
( を遣( う means to be considerate or careful around othersHere it means constantly minding manners and acting properly around those classmates.
疲
( れちゃう adds an unwanted-result nuanceちゃう is the casual contraction of てしまう.
In this line, Chiya would “end up getting tired”, with the nuance that this is an undesirable result.