This page describes all of Lily Loud's relationships with her family and friends.
Her siblings generally
Since Lily's the baby of the family (literally and figuratively), her siblings tend to her every need, and take the best care of her. She is always happy to be around them, and is able to tell when something is happening, like in "Cover Girls", she knew to cry at the right time to distract their parents before they noticed Lincoln missed his curfew.
Sometimes, things happen to her, or it appears that something has, due to their conflicts and antics, they would then put Lily first in solving the problems they caused, as shown in "Chore and Peace", when Lily going missing in the mess.
In "Changing the Baby", her siblings try to implement their interests on her, because they had nobody that shares their likes.
In "Potty Mouth", her siblings become worried about being a bad influence on her when they hear her say something that sounds like a swear word, and try changing their behavior so Lily has something better and more positive to imitate.
Out of all ten of Lily's older siblings, Lincoln and their three oldest sisters (Lori, Leni, and Luna) appear to be the ones who spend the most time with Lily.
She and Lincoln really love each other. Lincoln is one of the siblings who often carries Lily, changes her diapers, and burps her. He's very protective towards her, as he is usually the quickest to save her if she is falling, for instance, he was the one searching for her the most when she went missing and saved her from Lisa's seemingly dangerous experiment.
In "Changing the Baby", Lincoln spent his day with his sister Lily who was shown to enjoy doing so, though instead of becoming like Lincoln she instead chose to keep a hold of her blanket.
In "Two Boys and a Baby", he babysat her and learned it isn't as easy as he thought it would be. She and Lincoln are the two Loud kids who find clothes uncomfortable, which they can relate best through this.
In "Baby Steps", he takes care of her after she hurts her thumb and gives her a cookie when she heard Clyde mentioned it.
In "Room With a Feud", Lily and Lincoln become roommates, but the latter is unable to get any sleep due to the former's noise and poo from her diaper.
In "Potty Mouth", Lincoln accidentally swears in front of Lily.
She and Lori have a good relationship, and likely due to their large age difference (at sixteen years), Lori tends to act more like a motherly figure to her youngest sibling.
In "Cover Girls", Lily dresses up as Lori at once point.
In "Potty Mouth", Lori accidentally swears in front of Lily.
In "Room With a Feud", Lori steps on Lily's phone by accident which causes the latter to post embarrassing images of the former on the Internet.
She and Leni have a good relationship, and after Luna and Lincoln, Leni seems to spend the most time with Lily.
In "Changing the Baby," Leni tries to implement her interests on Lily, because she had nobody that shares her likes.
In "One Flu Over the Loud House," Leni prevents Lincoln from firing chicken soup at Lily, who was sick.
In "Back in Black", Leni plays with Lily.
In "Potty Mouth", Leni accidentally swears in front of Lily.
In "Spell It Out", Leni was seen holding Lily in the photo.
Luna has a cute relationship with her baby sister. Lily seems to enjoy being with her. As shown in most episodes, Luna seems to spend the most time with Lily, and is the one who usually carries her when they and the rest of their siblings are on the move.
In "Potty Mouth", Luna accidentally swears in front of Lily.
She and Luan have a good relationship.
Luan likes making Lily laugh and feel happy, although Lily doesn't seem to find a lot of Luan's jokes and puns to be that funny.
Luan plays with her while wearing her Groucho glasses in "Picture Perfect".
In "Out on a Limo", Luan plays Peekaboo with her by messing with the partition window in the limo.
As demonstrated in "Homespun," Luan understands Lily's babbling and can easily translate it to English.
In "11 Louds a Leapin'", Lily make raspberry sounds after Luan told one of her Christmas-themed puns.
In "Potty Mouth", she, along with Lucy, are the only Loud siblings who does not swear in front of Lily.
In "Potty Mouth", Lynn accidentally swears in front of Lily.
In "Spell It Out," she, Lana and Lola play canoeing.
In "Lynner Takes All", Lily is stacking blocks, and Lynn turns it into a competition and stacks more blocks higher.
She and Lucy have a good relationship.
In "Linc or Swim" Lucy took care of Lily by rubbing her body with sunscreen.
In "Changing the Baby," Lucy tries to make Lily a goth because no one else shares her interest.
In "Potty Mouth", she, along with Luan, are the only Loud siblings who does not swear in front of Lily.
She and Lana have a good relationship.
In "Potty Mouth", Lana accidentally swears in front of Lily.
She and Lola have a good relationship.
In "Changing the Baby," Lola wanted to have a tea party with Lily.
In "Potty Mouth", Lola accidentally swears in front of Lily.
In "Out of the Picture", Lily takes a picture of Lola on her tablet. Lola finds the perfect picture and she hugs Lily for helping her.
Lisa has a good friendship with her, as the both of them share the same room.
In "Changing the Baby" Lisa tries to use Lily on an experiment that appears to be very dangerous.
In "Study Muffin", Lisa reveals she tutors Lily for finger painting.
In "Potty Mouth", Lisa accidentally swears in front of Lily.
Her parents generally
Her parents take excellent care of her, and they make sure she doesn't get into any trouble.
In "Chore and Peace", they take her with them to get her out of the garbage caused by the kids' strike.
In "Future Tense", she is the Loud sibling not forced by her parents to do an extracurricular activity due to her being an infant.
They have a good relationship. Rita protects Lily as shown in "Chore and Peace", when she and her husband take her out of the garbage.
In "Come Sale Away", after Rita washes Lily's blanket, she gives it back to her.
In "Two Boys and a Baby", it reveals that Lynn Sr. looks after Lily while the rest of family goes to Aunt Ruth's.
Clyde and Lily seem to get along pretty well whenever they interact with each other. Just like Lincoln and his sisters, he can't resist the baby of the family.
In "Changing the Baby", Clyde fears that Lily will replace him as Lincoln's new best friend and tries to win Lincoln back by dressing up as a baby. When he realizes how cute Lily is, Clyde admits that he can't stay mad at her and decides to spend some time with her.
In "Overnight Success", Clyde was playing with Lily for a little while as Leni was shampooing his hair.
In "Two Boys and a Baby", Clyde helps Lincoln babysit Lily, thinking it would be an easy task, only to find out that it's much more difficult than intended. Lily at one point tears off strands of Clyde's hair, while she throws a tantrum.
In "Baby Steps", Lily wants Clyde to read her a story, which the latter contentedly agrees.
Despite being an inanimate object, Lily loves her teddy bear. Both in a friendly way and a romantic way. It's justified in that Lily's still just a baby and probably does not have a full understanding of the concept of romance.