She studies the device with a frown, deciding it looks far too cobbled together - is that a flashlight battery? - to be of much use. "You should get more sophisticated parts from the workshop," she comments critically, meaning her workshop, naturally. "Or just use my scanner." Her sensors may not cover the entire island, but she is sitting right on top of the rift's center, so she is getting very clear readings from it. And the Doctor has so much on his plate, having to take care of her, investigate the rift, and whatever other distractions crop up; he'd surely be thankful for some assistance.