which preposition should I use in the following context:

1. She always finds herself at the centre of awkward situations.
2. She always finds herself in the centre of awkward situations.

I feel 'at' should be used in this instance although it's just a feeling and I can be wrong. Also, is there a general rule which one of 'at' and 'in' should be used while talking about 'abstract things' rather than more concrete things like buildings etc.