。
This time, she's the one who fell into the trap.
Literal
She [topic-は] this-time [contrast-は] herself [subject-が] trap [in-に] fell-into.
The structure 彼女は…自分が… is a classic 'X (topic), Y (subject)' split: 彼女 sets the topic, then 自分が ('she herself') singles out the subject of the predicate, with exhaustive-listing が emphasizing 'she, of all people.' The set phrase 罠にはまる ('fall into a trap') uses はまる ('fit snugly, get caught in') with location/goal に. はまる has expanded to figurative uses too: a mystery 罠にはまる, but also a person ハマる ('to be hooked on, to be obsessed') with a hobby. 今度は ('this time, in turn') hints at a switcheroo — perhaps she had been the one setting traps before.