At some point during the orgy, maybe near the very end, a wired large tree with various vines hanging off it with endings looking almost phallic shape had been formed by the juices of the mating nymphs.
"oh well done sisters. Well done indeed" Margaret called out in joy. as she spoke a few nymphs moved towards the tree and for each one that did one of the vines quickly moved to spear a waiting nymph vigina, taking root and depending on the nymph brought her to her knees, coursed her to collapse onto her back or even let her move closer and get seated at the tree's base...
...but regardless of result the nymphs were joyful.
"that's a nymph tree isn't it?" Rachel asked. "yes indeed" Margaret proudly answered "these girls who like you were until now guests who longed to remain in the Forest, so they've chosen to be impregnated. would you like to join then and retain the pleasures of being a nymph forever?".
"yes... yes I'm joining them" Rachel happily answered as she moved closer and once close enough welcomed it as a vine speared her vigina and bringing her to her knees as it took root, the seman-like sap from the tree then traveling through the vine into her to fertilize the eggs within her to create daughter nymphs...
...and prevent Rachel from ever leaving the resort: