Why does Charlotte go to all this trouble for "some pig?" Because he's her friend, and that's all the reason she needs. Or to quote the book...
Wilbur: Why did you do all this for me? I don't deserve it. I've never done anything for you. Charlotte: You have been my friend. That in itself is a tremendous thing.
Following a Tear Jerker moment where Wilbur finally sees all of Charlotte's children hatch only for them to recklessly abandon him due to their natural instincts, it seems he's never going to have any friends like Charlotte again for as long as he's around...until three runts of the sac miraculously emerge right where Charlotte used to preside. He instantly befriends and helps name all three of them, now assured that for the rest of his life he will now have company, and a happy little reminder of the spider who helped save his life.
The very last line of the book, which also made it into the final narration of the 1973 film: "It is not often that someone comes along who is a true friend and a good writer. Charlotte was both."
Animated Examples
Fern's song to Wilbur, "There Must Be Something More".
Along with that, the montage showing Fern raising Wilbur.
Charlotte's lullabies to Wilbur.
Charlotte's last moments with Wilbur.
In a cross between Heartwarming Moments and Tear Jerker, the film shows a montage of Wilbur and Charlotte's time together as she sings her final song in the last moments of her life.
Fern patting Wilbur and wiping away his tears when she and the other humans find him mourning Charlotte's death. Even though she's been spending less time with Wilbur and focusing on Henry Fussy, she still cares enough to comfort him.
Blink and you'll miss it: Henry Fussy gets back to town from visiting his grandpa just in time for the fair. He takes Fern on the Ferris Wheel, and when the height frightens her, Henry puts his arm around her. In response, Fern moves closer and gives him a very sweet look.
Live Action Film Examples
Wilbur being the first farm animal to quickly accept Charlotte despite her looks, and shooting down the other animals' disgust.
The way Charlotte lands on Wilbur's snout is very...sweet. Just something heartwarming that deserves mention.
Specifically, this dialogue crosses both tearjerker and heartwarming:
Wilbur: Please, Charlotte! You have to come down! You've done so much for me! Charlotte: And it was my great pleasure. Wilbur: Please come down, Charlotte! Please! There must be something I can do! Charlotte: No, Wilbur. Don't you know what you've already done? You made me your friend. And in doing so, you made a spider beautiful to everyone in that barn. Wilbur: I-I didn't do anything, Charlotte. Y-You did it all. Charlotte: No. My webs were no miracle, Wilbur. I was only describing what I saw. The miracle... is you.
The barn animals take turns keeping Charlotte's egg sac warm throughout the winter. Even Ike.And Templeton.
Animated Sequel Examples
In the 2003 DTV sequel, we have Wilbur's friendship with Cardigan, a black lamb neglected by his own kind. Wilbur was one of the few animals on Zuckerman's farm to befriend him, knowing full well what it's like to be the runt of the litter (or in Cardigan's case, the Black Sheep) and to be denied the company of others.
