。
She's at the hotel right now.
Literal
She [topic-は] now hotel [at-に] is.
Bare and functional — 彼女は (topic), location (に), 今 (time), いる (existence verb for animate beings). The same skeletal frame underlies a vast number of basic 'X is at Y now' sentences in Japanese. The locative に attaches to ホテル to mark place of existence; if you wanted to say 'is doing something at the hotel,' you'd switch to で.