。
She spoke with a touch of sarcasm.
Literal
She [topic-は] a-little sarcastically spoke.
皮肉っぽく (ひにくっぽく) adds the suffix ~っぽい ('having a quality of, -ish') to 皮肉 ('irony, sarcasm'), then converts to the adverbial く form. The 少し ('a little') softens it — she wasn't overtly sarcastic, just slightly. The ~っぽい suffix is productive for suggesting a quality without full commitment: 子供っぽい ('childish'), 忘れっぽい ('forgetful').