I never had her end up incapacitated. Not much point when you basically have enough to spend little time searching 2-3 systems.
In the context of the game, you'd have to spend several days exploring each star system and viable planet. You're not necessarily pressed for time (not more than you are in the game already technically), but you don't want to spend a huge amount of time waiting chasing a red herring in each system.
I like the tension that is caused between Shepard and James when James realizes just how far my Shepard is willing to go to get the information he needs, to the point where he's more than willing to let Ann die if it gets him to Leviathan. I usually raise the shield in time to keep from crippling her, but I dislike how it's portrayed, where Shepard orders James to activate the shield (especially after one or two interrupts telling him not too.) I'd have preferred if James (since he's going on about stopping it) acted on his own, against Shepard's wishes. It would be an interesting point of contention between the two. I RP that that's a point where James, who has that hero worship towards Shepard to an extent, realizes that Shepard isn't the purely good noble man that alliance propaganda has him made out to be (even after getting to know him after guarding him for 6 months and probably aware of his reputation for results-at-all-costs), and that Shepard is willing to throw innocent lives under the bus to meet his agenda.