> Big mistake, but she owned it. Just a tonal note. Saying 'Big mistake' implies to me that it's meant sarcastically in the sense of 'Big deal' or 'Big whoop',

> Big mistake, but she owned it. Just a tonal note. Saying 'Big mistake' implies to me that it's meant sarcastically in the sense of 'Big deal' or 'Big whoop', which I gather from the rest of your sentence is not what you intended. I would not have read it this way from the phrase 'A big mistake, but she owned it.'