A/N- This is what I think Morgan's secret lab to look like. Just scatter a few gadgets here and there. 

"Come in, but quietly; if mom comes to know then I will get killed." Morgan whispered, while leading the Avengers to her 'secret' underground lab. Once they were inside, Morgan asked Meg to place her hologram in her main lab so as to fool her mom for sometime. "See, we cant talk too loudly here, even though this lab is supposed to be 'secret', it is not." Morgan told the other five. They all hummed in agreement. 
"This lab is giving me vibes of Tony's lab, what do you think?" The guy with the shield and metal wings said. "Just a little more advanced," Morgan said and some chairs popped up. They all took a seat and Morgan said, "My questions, your answers, agreed?" "Agreed" The guy with the spider-costume asked. Morgan asked him to take off his mask as he looked 'ridiculous' wearing that. He did, and said, "Do you remember me, like a little bit?" Morgan pretended to think hard and then said a flat "No". "First question, Introduce yourselves." Morgan said and then she got to know that the guy with the metal arm was James Buchanan “Bucky” Barnes and the guy with the wings and the shield was Sam Wilson. 
"Is that... Vibranium?" Morgan asked, astonished. "Yes" Sam said, smirking. "I did not ask you." Morgan said and Meg spoke up, confirming that Sam was right. The archer of the group was Clint Barton by name, the lady with brunette hair was Wanda Maximoff and the guy in the spider-costume was Peter Parker. 
"Ok, now that I know your names, I will fire the next question, which is.... why are you here?" Morgan asked. "To take you to the 'outside world', I guess." Wanda answered. At this Morgan wanted to do a jig, but she kept herself intact and asked them some questions about the 'outside world'.
"You know what, I just wanna ask you one question; in which school do you study?" Peter asked. "We searched for you everywhere!" "I am home-schooled." Morgan answered. "Who are your friends here?" Wanda asked. "Just one, and that is Meg, a.k.a. Morgan's Electronic Genius." Morgan said with a little sadness in her tone. "Then what do you do for recreation?" Peter asked. "I am not like you, I don't need friends, or maybe I do, but why does it matter now? And as for what do I do for recreation, what do you think this lab is for?" Morgan said. "Ok now you can go on with your questioning." Sam said. 
"How come you know my location?" Morgan asked. "You tried to hack some files related to your dad and his works." Sam said. "And I succeeded" Morgan said, looking very smug. "But I did that an year ago!" "Yeah, we tried to track the computer used, and failed, but we did not give up hope to find you, and see, we succeeded." Peter told her with a smile. "This was due to the little amount of brain you own or something else?" Morgan said, sarcastically. Everyone ignored her comment.
Morgan sighed. "I see that you guys really wanted to meet me, as you broke open four barriers, the last one being an electrical one, but the thing I fail to understand is what took you so long?" Morgan asked. "Pepper happened." Clint said. "How?" Morgan asked. "I will tell you how." A new voice filled the room, which Morgan knew belonged to her mom. "Meg, why on earth did you not warn me that she is coming?" Morgan asked Meg. "You 'ordered' me not to interrupt you while you are talking, so I didn't, but you see, you shouldn't hide something from your mom." Meg said. "You called her here, right?" Morgan said. "Yes and no, you see, your mom got fooled pretty good by that hologram, but I went ahead and flickered the hologram; she asked where you were, and I told her; Morgan I did it for you, we don't know whether these people are good company or not" Meg answered. "Whatever." Morgan mumbled. 
Wanda and the others got up. Wanda went up to Pepper and asked, "Why?" 
"I would rather like to answer my daughter's question first," Pepper said, sternly. "So do that," Morgan said. "I don't know how you guys found us, but get this thing straight: Morgan will not go anywhere." Pepper said while staring at each one one of them, one by one. "Why?" Morgan moaned, "I wanna go, with them, away from this Rapunzel's tower, I wanna be free." "Morgan, I kept you away from all this thinking that you when you grow older, you would not want to indulge in these suicidal fights, but I see I was wrong." Pepper told her daughter.
"Mom, you know, "absence makes the heart grow fonder, and now I want to go with them, please..." Morgan pleaded. Pepper literally ignored her pleas and went on, "I have already lost Tony due to you guys, and I will not be able to bear my daughter's loss." "Tony did not die beacause of us, he-he-he sacrificed himself on his own will!" Wanda said. "Who do you think Morgan has the blood of?! It is Tony's! If the time comes, then I know that she would not think twice before doing something crazy and would also  sacrifice herself!" Pepper said-screamed. 
After this there was an awkward silence, as no one knew what to say, or how to react. 
"Mom, if I say that I would not fight like them or indulge in any such activities, then would you let me go?" Morgan asked timidly
"Morgan I have already given my answer" Pepper said, sternly.
"Which is," Morgan said
"A big, fat, NO." Pepper said.