Is 相手……全然甘えない… idiomatic?


I've come across the following dialogue in a piece of fiction I was reading
today;

> あの子さ、あたしら相手だとついお母さん役しちゃって、全然甘えないじゃん？

I'm not sure if I completely understand what the speaker is saying here, I was
wondering​ if the above contains some sort of idiom?

Is it perhaps similar to this;

> 相手の好意に遠慮なくよりかかる To accept someone's favour without reserve and depend on it

Thanks in advance




Yes, 甘える here means exactly that; to let others help her, instead of doing
everything by herself. あの子 behaves as if she were a mother, but the speaker
wants an equal relationship where everyone takes it easy and casually helps
one another.

See: [Meaning of 素直に甘える in the following
sentence](https://japanese.stackexchange.com/q/44347/5010)

