I think she probably thought he’d do it because he wanted to more than as a favour for her.
I’d call Veronica and Weevil’s relationship ‘complex,’ to say the least. They’ve gone back and forth so many times it’s hard to characterize where they stand at this point. But if I remember correctly, it was Veronica who got Weevil the job in Hearst’s maintenance dept. (through a good word with the Dean, I think). Maybe she thought she was one up on the favor scale. And I don’t think you can count what Weevil did to Thumper last year as a favor to Veronica–he had plenty of personal reason to root out who was dealing with the Fitzpatricks.
Keith: “Hi. My name is Carson Drew. This is my daughter Nancy.” 
Veronica has done things for Mac for free, so I don’t know what exactly the friends rate is. Of course Veronica needs Mac if she needs more geekiness than VM can muster, but she also calls on Weevil (shrug)
Brian
What I don’t understand is, even if the roommate is the one who went to the clinic, why did SHE get the bookmark. The right-to-life group sent things to Keith as Veronica’s parent. This, of course, assumes that I don’t ask how they were able to figure out who Veronica really was, in order to send the information to Keith, in the first plase.
Could be a bunch of ways… could be that RTL sent it to her (either accidentally, or because they couldn’t find a parent/friend.) Or maybe whoever they sent it to found it funny… “Hey, did you get pregnant and not tell me??”