When you say it will be used on a digi cam I suspect that means she will be losing the auto features for the lens, or is this a late model bellows unit that utilizes all the auto features such as exposure in particular.
Depending on what she wants to do the principles will most likely be the same. Meaning that if it's an auto-unit anything auto- will stay auto- whether digital or film and if it's not then it's not. With the exception of reciprocity I can't think of anything off the top of my head that would be very different between the two.
When you say it will be used on a digi cam I suspect that means she will be losing the auto features for the lens, or is this a late model bellows unit that utilizes all the auto features such as exposure in particular.