The moment she poisoned the monkey, it should have tasted like her "poison". Spiders only poison their food if it's the only way to kill them. If the prey is trapped and no possibility of damaging the web further, they will let the prey tire out and then wrap it before eating (because venom taste terrible).
On a side note, Spiders do NOT have poison, they have venom. It's different. An easy way to remember is, if it bites you, it's venom. If you bite it, it's poison. (snake/spider bite vs eating food that went bad or was contaminated/poisoned).
Big difference is poison is harmful if its swallowed or breathed in, however you could generally consume venom with no harm done (assuming you have no damage to the mouth or stomach(cuts etc)). Venom requires it to be injected into the tissue, under the skin, to cause harm. But please, do not drink venom, the slightest abrasion to your gums may affect you!