Mary moved backwards, trampling countless houses and passerby in a reckless stampede. Once at a safe distance, Mary watched as the spider grew and grew. The larger it got the slower it expanded.
It seemed a bit dazed from its change. Although near Mary's size, it grew yet more. Mary knew that she might not get a better chance than this and leapt forwards onto the arachnid.
The spider shook itself around, trying to get Mary off of itself. For a moment she faltered and almost fell, but with a flutter of her wings she managed to stay stable. As she lowered she plunged her mighty spear into the gargantuan beast.
Despite being much sturdier than her, Mary had better armaments than the spider and was able to easily tear through its chitinous body. Mary took a long sip of the sweet ichor, relishing its refreshing taste. Suddenly, Mary felt a jolt as she was lifted up into the air and off of the spider. Flittering her wings, she glided a bit away from the beast before landing.
The spider was now bigger than her, near 130 feet, its growth nearly stopped. But despite being staggered from the fierce blow, Mary could feel herself growing again. Possibly to become even bigger than the spider.