Firstly, in regard to Lily and James's relationship, there are several things to consider. Whether or not they were close friends, they did live in close proximity to each other for years, and by Remus Lupin's account, James grew up a bit in sixth year which allowed a friendship to develop between James and Lily. They got together in seventh year where they were Head Boy and Head Girl, and they married a little over a year after school ended.
Secondly, as far as Lily's friends, what about Dorcas Meadowes?
Thirdly, I can't say for certain, but I'm fairly sure that one of the Marauders said that no one knew about the Marauders's animagus forms.
And as far as a gift from Lily to James, I really like the idea that Willow Rosenberg had with Lily giving James a cat, and the Potters do have a cat post-Hogwarts.
Did Lily know about the Marauders' Animagi forms and Lupin's lycanthropy? I want to say that she did, but I can't think of any canon evidence (not a super canon person unfortunately) to support this.
I'm fairly certain she did, because she wasn't stupid and I think she noticed it, but I'm not sure if I'm thinking book canon or movie canon. Her Patronus was a doe though (DH), so I think she knew her husband was an Animagus. I honestly don't know if I have a legit canon reference for you though.
Er...I don't have the specifics, but either Sirius or Remus told Harry that no one knew of the Marauders's animagus forms, not even Dumbledore.
Aida - there's no actual canon evidence from the books that Lily knew about Remus or them all being Animagi, but I think it's a fair assumption that she did. Once she's involved with/married to James, he is not going to be able to keep his nocturnal wanderings secret from her.
If you look at the letter she sent to Sirius, she calls him and Peter by their nicknames (showing closeness to them) and I can't imagine her not wanting to know how they got their names.
Personally, I think she knew Remus was a werewolf before she was officially told. Snape's words must have struck a chord, she just didn't want to believe it.
From what Slughorn said, Lily was very intellagent. I think that she, like Hermione, might have had a theory plus evidance. She might not have wanted to believe Snape, but I think she did.
I think that Lily did believe Snape when he said about his suspicions but I think that she felt some loyalty towards Remus. I think that she shot down what Snape was saying because she didn't entirely trust him not to tell his "creepy" friends.
As for the pet names I think she would know them as she dated and eventually married James and in the letter that Harry found in Sirius's bedroom she calls him padfoot.
Also, I don't remember if this is from the movie or the book, but doesn't Remus say she helped him out with a hard time or something like that? I would guess that it would have to do with his lycanthropy.
And honestly, simply judging by the fact that Lily married Remus's best friend, thus spending a lot of time with James and the Marauders and being characterized (by Dumbledore I think?) as extremely kind, I think that it is most probable that he would have told her if she hadn't guessed already.
I haven't read the other five pages of this, but I was just wondering: Does anyone else think Lily was a little hard on Snape when he called her the M-word? I mean, he was upset, he was HANGING UPSIDE DOWN, and he probably wasn't the most clear-headed person ever. And this is just me, but *my* very best friend has called me a b**** before now, and I
'm obviously still friends with her. I get that Lily was a little hot-headed, but this just strikes me as weird.
(This is coming from a Snape lover, so I might be biased).
I admit that it struck me as kind of odd for Lily to freak out that much about it, because she wasn't raised being told how bad of a word it was... Not to say that she's not old enough at that point to know what an insult it is. It's entirely possible that the whole fight could have just built up over time. It's implied in Deathly Hallows (through Snape's memories) that he didn't change in the blink of an eye. It was gradual, and the whole "upside down" event and snapping at Lily, in my opinion, just sent her over the edge.