If the snails have nothing to eat they can easily do damage to fancy goldfish....
She deinately needs to suppliment their feedings.
Rusty
PS She should be giving her goldfish fresh veggies every other day or so..
Dark leafy greens, squash, zuccini, peas etc. If she puts them in in the morning she should always take out any uneaten food in the evening. This will also help feed the snails.
All around she will have healthy happy gfish & snails!