。
She named the kitten Jaguar.
Literal
She [topic-は] kitten [object-を] Jaguar [as-と] named.
XをYと名付ける ('to name X Y') is the standard naming construction — を marks the thing named, と marks the name itself (in its quotative-like role of 'as'). 名付ける is itself a compound verb: 名 ('name') + 付ける ('attach, fasten'). Same pattern works with 呼ぶ ('call'): XをYと呼ぶ ('call X by the name Y'). 子猫 ('kitten') is 子 ('child') + 猫 ('cat'). Naming pets in Japan often draws on katakana names, English words, or fanciful imagery — Jaguar for a kitten is a winking choice.