Rabbits can have worms, but it's not all that common. Did this person say why she thinks they may have them or is she someone who simply worms rabbits routinely. (IMO, routine medication of rabbits is not a good idea.)
I feed my rabbits pumpkin seed every fall/winter. We grow our own mainly for the rabbits and the seeds are an excellent safe food that will also kill internal parasites. What a good deal! You can buy pumpkin seeds at a health food or bulk food store (get raw ones if you can, in or out of the shell) and sometimes you can find them at feed stores, sold as squirrel food. That would likely be your cheapest source. Start with just a few and work up until you are feeding a small handful (a couple of tablespoons). Continue for a couple of weeks and your buns should be cleared out of anything that might have been there.
Oh, just a reminder to NEVER feed seed intended for planting as most of them are treated with a fungicide that might be harmful to the rabbits.