:: action
[ Rose presses her lips together, considering this. ] If we had someone here like that, someone that'd help us, we might be able to make progress. The TARDIS is a ship, but she's a sentient ship that is able to navigate space and time. Me and UNIT took her abilities and sorta...cannibalized 'em, focused 'em, funneled 'em and used 'em. She was willin' though. Takin' the moral issue outta it, I think we'd need them to do it voluntarily.
[ Because morally, it'd have to be voluntarily as well. Rose is just pointing out that the willingness is necessary. She's fairly certain that if the TARDIS hadn't helped in her own way, guided them in the right directions, that they'd never succeeded back home.
Of course, she's leaving out that doing so had killed the TARDIS.]