。
She peeled the sticker off the window.
Literal
She [topic-は] window [from-から] sticker [object-を] peeled-off.
引き剥がす is a compound verb 引く ('pull') + 剥がす ('peel, strip off') giving 'peel off, strip away' with an emphasis on the force of removal. Used for stickers, posters, scabs, paint, anything that's been adhered or stuck to a surface. ステッカー is a katakana loanword from English. The combination of 引き剥がす with から (source of motion) gives the action of yanking the sticker off the window.