But she wants to start with the pinstripe she already has, right?
So yes, if you pair your pinstripe to a pied, and if you get lucky and hatch a pinstripe het pied male, then you can breed him back the next season. So that's two extra years of waiting, but maybe you'll get a pinstripe pied out of it. And pinstripe is one of the few pattern genes that really plays well with pied.
^ Of course, I didn't get lucky with my pastel x pied pairing last year, and both of the pastel 100% hets I hatched were GIRLS. The vet was so perplexed when he sexed them as female and I was DISAPPOINTED.