Here's what some digging in the GECK dialogue tree turns up:
Billy: "Oh! Sorry, I guess I got ahead of myself, huh? Maggie's nine, sweetest little girl you'd ever care to meet. We take care of each other."
Billy: "I ain't never had a daughter, but if I did, I'd want her to be Maggie. I took her in when her parents got killed by Raiders. That was two years ago."
She was seven when he found her. Also, his conversation implies that he was riding with the caravans for years, including before he found Maggie.
In fact: "Me? I deal with the caravan suppliers. I used to ride with those guys, so they cut me some good deals. Helps keep the town supplied."
Combined with: "It was a pretty bad scene. Small settlement up north. I'd stopped in to trade some salvage, and the whole place had been wiped out." - implies he was still working with the traders when he found Maggie.
Probably settled down in Megaton to raise her, since a traveling caravan can be a bit tough to raise a kid in, especially in the wasteland.
Maggie is also aware who it was that killed her parents, as her conversation includes:
"Billy does! Have you met Billy... Billy Creel? A long, long time ago, he saved me from Raiders!"
"They... killed my real parents. But Billy showed up before they got me, and now he's like my daddy... sort of..."
(Hey, when you're nine, two years ago
is long, long ago.
)
Here are the conversations they have, which indicates Billy likes Moira (either as a friend or something more, or perhaps both) and Maggie has a crush on Harden.
The later especially argues against Billy molesting or even being attracted to Maggie beyond a father-figure level.
And would you really take
Moriarty's word over Billy's? "Oh he seems nice, he must be hiding something." or what? That's pretty sad.
I can post Moriarty's conversations if you like, so you can see what a nice and caring individual he is. :rolleyes:
Alternately, you guys have been watching too much porm.
Maggie greets Billy:
Maggie: "Billy, I want to talk to you..."
Billy: "Anything for you, honey?"
Maggie: "You said we could have that talk sometime. You know. About boys. I'm ready! I'm ready now! There's some stuff I need to know. Like, really bad."
Billy: "Whoa! Whoa now, honeybun! Let's ah... Let's slow down a little, okay? You got a lot of time left before that stuff is important. All right?"
Maggie: "*Sigh* All right, Billy. But you can't avoid the subject forever, you know..."
Billy: "I know, I know, sweetheart. Now you run along, okay? Billy's got some thinkin' to do."
and
Maggie: "Billy, can I talk to you about something?"
Billy: "For you, sweetheart, anything. What do you need?"
Maggie: "It's about Harden. I think I want to... kiss him. But I don't know if I should. Well, I think I should, but I don't really know HOW. What should..."
Billy: "Oh! Well... Well, now, you know Maggie sweetheart that boys and girls, umm... Aw hell, girl, can't you talk to Moira about this stuff?"
Maggie: "Geez, Billy, you're so timid with this stuff. I won't be a kid forever, you know."
Billy: "Hey, would you look at the time! Sorry sweetheart, I've got, um... somethin' to do..."
(This one is hilarious to listen to.
)
Billy greets Maggie:
Billy: "Hey, Maggie! How you doin', darlin'?"
Maggie: "Yeah, Billy?"
Billy: "Well, I was thinkin', Sweetie Pie... Sometime soon, we should take a trip. Just you and me. Maybe visit Rivet City or somethin'. Would you like that?"
Maggie: "Oh, yes! Please, please, please! Can we Billy? We could have so much fun. More fun than we could in Megaton, that's for sure!"
Billy: "Ha ha! I just love seeing you happy, sweetheart."
Maggie: "You're the best, Billy!"
and
Billy: "Hey! Sweetie-pie!"
Maggie: "Yes, Billy?"
Billy: "You know, I got to thinkin'. You and I should do some scavengin' sometime soon. See, we find us an old bike, and get Moira to help us fix her up!"
Maggie: "You mean it? Oh Billy, thank you! Thank you so much! I can't wait!"
Billy: "Well all right then! It's settled! I'll set my affairs in order, as they say, and we'll sit down and plan this thing out."
Maggie: "Thank you, Billy. I just... thanks."
(This last implies she's really flattered to be included in such a grown-up thing as a scavenger hunt and fix-up.
)