Her main interest has always been the Victorian period, but looking at the acceptance rate on her course (shared by
@yeya upthread), I'm assuming she chose it for the likelihood of getting a place. If Ruby's feeling uncertain about her offer, maybe it's because she's prioritising Oxford over the course content, i.e. she's just not that interested in Early Modern lit.
Her subdued response might be due to the delay between receiving the news and uploading the video. She seemed extremely happy before going to Italy imo. This is when she was posting all of those upbeat TikToks and Wes Anderson clips. Maybe she's just had time to calm down.