Victoria Watts

Victoria Watts is a NPC (and likely an android) in Fallout 3. She is involved in The Replicated Man quest.

Ms. Watts is involved in an organization called The Railroad which, like it's namesake, works to protect escaped slaves, mainly androids. She has traveled to Rivet City to protect the identity of Harkness. After you are asked to hunt him down by The Institute, she will request that you feign his death using an Android Component that she gives you. If you assist her in saving Harkness, she will later ask you to not speak to her again (for their safety).

Appearances
Victoria Watts only appears in Fallout 3. When you have started The Replicated Man, she sometimes appears when you go outside. If the quest is triggered outside Rivet City, perhaps in Big Town and followed up on in Megaton, she may confront you before you leave Megaton.

Aside from her travels to seek you out, she can be found on the upper balcony of the Rivet City Marketplace, near the pool table.

She also appears under the water when leaving from Pinkerton (if you leave from the bottom exit) and she waves a knife in her hand and just stands there underwater. This is most likely a glitch but its pretty funny. She can also be seen just swimming in this hallway, without weapons.

Also her appearances may be random as she has been known to be encountered almost anywhere regarding the The Replicated Man quest.

She can appear almost anywhere, including inside Little Lamplight, which of course makes no sense.

Appearance Triggers
Rather than being a random encounter, Victoria Watts seems to home in on you. Once triggered, she starts running towards you from Rivet City. Thus, the time and place of the encounter depend on where you were when you triggered her and where you happen to be by the time she's covered the distance to you. As such, you can potentially meet her anywhere, including in rather incongruous locations and situations (such as inside of Arlington Library.)

The actual trigger for Victoria's homing instinct appears to be using dialogue options with other NPCs to ask about the android. This is because when Victoria appears, she confronts you about asking these questions, giving you the impression that she's ready to fight. The availability of these android-related NPC dialogue options, in turn, seems to depend either on getting the quest from the main source in Rivet City, or by finding at least 2 holotapes or other notes about the android in other locations. If you have not been to Rivet City, therefore, but just innocently use the android-related dialogue options, your subsequent encounter with Victoria can be somewhat surprising, especially if it happens during a firefight (see below).

Victoria's purpose is to present the player with an ethical choice in this quest. As such, she is immortal until she delivers her message to the player. This can cause problems if the player is currently in combat. Victoria fast-travels to the player's general vicinity and then enters the 3D world at the farthest creature-appearance distance from the player. From this point, she runs toward the player. Because she is friendly to the player at this point, creatures hostile to the player will attack her. She completely ignores them (she's after you and only has a knife anyway) and they can't kill her. As a result, Victoria can easily run up to the player closely pursued by a whole train of enemies. This can lead to combat being interrupted by her speech, and to her being hit by stray bullets.

Speculation
Victoria Watts does not appear to be an android herself. This is because if she dies after giving you the android part as part of the quest, her body will not have any more android parts on it. On the other hand, Victoria appears to be completely immune to the Mesmetron, so perhaps she really isn't human. But then, many named NPCs are also immune to it.