、、。
She's cute, and on top of that, very kind.
Literal
She [topic-は] cute, [on-top-of-that-そのうえ], very kind is.
そのうえ ('on top of that, moreover') is a sentence-connector that adds a reinforcing fact — typically positive on positive or negative on negative, never mixing polarity. Structurally it's その ('that') + 上 ('on top') — pointing back to the previous clause and stacking another fact onto it. かわいらしい ('cute, lovable') is the い-adjective form related to かわいい — slightly more elegant or written, but with the same core meaning. The adverbial form かわいらしく acts as the predicate of the first clause through the i-adjective stem-form chaining (~く・~), the written-leaning equivalent of the te-form.