(Reader is 3 months here)
Percy
It had been at least 3 months since he took you in and Percy couldn't have been happier. You were just what he needed after Annabeth dumped him and you helped him with his Tarturus flashbacks. Of course Percy had a job and that sometimes got in the way of you guys spending time together, but Percy is a single dad with no other source of income soooo..... Anyways, it was a pretty average day for you two. Percy was home watching TV in the living room while you were napping in the other room. All was peaceful.... until someone knocked on the door. Percy begrudgingly got up from the couch and opened the door to find his ex, Annabeth, standing out the door. She looked like shit really. Her hair was unkempt and her eyes were rimmed with red. It didn't take a genius to figure out she was miserable. Percy let her in while looking at her in surprise. Neither of them said a word. They just stared at each other. While Percy stared at her and Annabeth tried to look anywhere else but him. This continued for several minutes until you woke up and started crying for your father. Startled, Percy ran to your room and took you out into the living room with, shushing you in the process and forgetting Annabeth was there entirely. It wasn't until Annabeth spoke up did Percy acknowledge her. "Percy.... Why do you have a baby?" She said in the most broken and timid tone Percy had ever heard. "Uh right.... Annabeth this is my daughter (y/n). I found her the night you dumped me." Percy replied. Annabeth visibly flinched at the mention of the night she dumped him. "I see.... Um.... I wanted to ask, who's her mother?" It was Percy's turn to flinch. "Her mother was a dying homeless woman I found on my way home after.... you know," Percy said awkwardly. Annabeth hummed in understanding before starting to ponder something. Annabeth than started watching you and Percy. You were messing with your father's messy hair and trying to pull it. He stopped you and gave you his hand instead and you started playing around with his fingers. It took Annabeth a few minutes before speaking again. "Percy....," she said grabbing Percy's attention off of you, "Is it ok if I stay with you two for a while? I just recently lost my job and was evicted from my house due to not being able to pay rent. It's ok if I can't. I'll ask Piper and Jason if your not comfortable with me being here." Percy looked at her a second before answering. "No no no no! You can stay here," Percy said waving his free arm at her to emphasize his point, "I need a babysitter for (y/n) when I go to work anyway. And I'd rather have someone I've known most of my life watch her than a complete stranger. Besides, what kind of.... friend would I be if I let you live on the streets" Annabeth frowned at the word friend, but quickly recovered and thanked Percy with a strained smile. Percy smiled at Annabeth and handed you to her. Also, lets just say Annabeth made a few Iris messages to the rest of the 7 telling them about you.... yeah expect a visit from all of your aunts and uncles soon
Jason
Everyone knew you existed already. Jason and Piper told them when they found out they were having you
Leo
To say Leo was expecting the 7 and Nico at his front door would be a lie. Well, he used to have a door. Let's just say, Jason set a lightning blot to it and made the door explode. Now he has a crying baby, aka you, an explanation on why Leo practically disappeared off the face of the earth, AND a door to replace. Yeah. To say they were surprised when they saw Leo rush off and return with a baby in his arms is an understatement. They were SHOCKED. Of course, they thought Leo and Calypso did the 'horizontal tribal dance' and that's why you were with Leo. But when they asked why Calypso wasn't there, well, Leo got very emotional and told them EVERYTHING. From when he found out when Calypso died to finding you on his doorstep and raising you on his own. He even showed them the note your mother left with you. By the end of his explanation, Leo was practically sobbing and he was pulled into a hug Hazel while you were in Nico's arms asleep. (I think that Nico and Hazel are the closest friends Leo has. Even if Nico is too tsundere and prideful to admit it. They get one Leo's pain because they went through it as well :) ) Nico had grabbed you out of Leo's arms when he saw that Leo was about to drop you. Nico is your favorite uncle now! Yay!
Nico
Nico had IM'd everyone when he went into hiding. He was basically warning them that the Avengers, he finally found out who the Comic Con freaks were at that point, saying that they may be looking for the 7 to ask questions if they knew where Nico was. You had coincidentally came into the convo when you started crying. Nico quickly calmed you down before explaining who you were and why you were with him. Expect a visit from your Aunt Hazel and Uncle Percy VERY soon.
Edit 6/14/18: Just doing some maintenance.