Clairvoyance is the ability to discern people who are not in the observer's presence.
Molly can see visions of people by thinking about them. She can also see glimpses of what that person is doing.
Molly can locate any person upon whom she concentrates. She can then indicate the person's location on a map. She was able to pinpoint Matt's Father to a specific room in an apartment building. Molly apparently needs to know something about a person before she can locate them. She asked Maya for a picture of Alejandro that she could use to search for him, but Noah believed that she could find West given only his name.
The manner in which Molly uses her clairvoyant powers to locate Maury Parkman's Apartment suggests that she actually has an "out-of-body experience" while using her powers, although she is able to maintain consciousness in two places at once.
Molly was unable to find the late Alejandro, showing that she is unable to detect dead bodies. It is unclear whether she is able to locate other non-living objects; she has not yet attempted to do so. However, she did describe her ability as finding people. Molly is capable of detecting other people near the ones she is looking for: she was able to detect Sylar not far from Monica Dawson.
When Rebel needs to find their family members and are unable to locate them, they enlist Molly's help to find them using this ability. She is able to find them all instantly with the aid of pictures shown to her. However, while during the rescue she detects Monica nearby, they are unable to locate her despite Molly still seeing her tied to a chair where they are. When Molly gets worried about West and Sparrow she uses this to look for them and apparently sees what they're up to as she instantly gets worried. Later, as everyone's trying to escape, she figures out where Monica is with her power. She realizes Monica is not there but in a hospital in Washington, D.C. After she gives Micah the address, the team use it to find and finally rescue Monica.