。
She's interested in learning new things.
Literal
She [topic-は] new knowledge [object-を] learning [nominalizer-こと] [to-に] interest [subject-が] exists.
興味がある (きょうみがある, 'to have interest') uses が to mark 興味 as the subject of ある. The whole thing one is interested in is nominalized with こと and marked with に: ~ことに興味がある = 'to be interested in doing X.' 知識 (ちしき, 'knowledge') covers both academic learning and practical know-how.