It's pretty clear (both here an in the WN) that she herself likes him. It's just Bertia being dead-locked on the idea of [True Route] and doesn't truly think of her own feelings and future. Even if prince is a bit forceful with all this earrings buisness, she made them herself. It was her idea. It's just Bertia had cold feet at the last moment.
I really dislike possessive characters most of the time. This instance though is but a small thing (for big ones see Otome Burikko and Hero Proposed to Me, But, where MLs just go full-on creep mode).