When we caught up with Megan, 23, at the Mark Hill Pick N Mix launch, it was clear she's super proud of her 17-year-old sibling, who she describes as being a "mini version" of herself.
"She is very feisty and opinionated but she's never really wanted to be famous," said Megan.
"[Being on TV] isn't her type of thing but she's doing it for me. She's currently finishing her A-levels at the moment and she's really brainy unlike me!"
"I'm not going to lie – we do row because we're so similar but since I've moved out we get on better," she said. "We used to row over clothes but we're fine now."
Typical sisters then, right?!
Megan praised Milly for always having her back and refusing to let anyone criticise her: "She's one of those girls that won't let anyone ever talk sh*t to me.
"I feel like the last couple of weeks, the only person that's had my back on the show has been [boyfriend] Pete. Obviously I've built good relationships with people, but as you grow up you realise who your true friends are and that's something I've learnt being in this industry.
"I've learnt who I can and can't trust but my sister will always have my back. It's good to have her on my side."
As well as meeting Milly on Wednesday night's episode, we were introduced to the girls' parents, Dave and Tanya, who were on hand to offer Megan advice on dealing with all the latest Essex drama.
They also gave her boyfriend Pete Wicks the seal of approval!
"My family absolutely love Pete – we're not round there often because I have my own house but my sister loves him and he's even met my dad and my brother," said Megan. "They didn't need to take him to the side and have a chat with him because he's a gentleman.
"My brother has a girlfriend and we go out as a couple – we double date which is so cute and nice."
Perhaps we'll be seeing her brother on screen next!
TOWIE continues Sunday at 10pm on ITVBe.
10 reasons why we want to be in TOWIE:
Follow us on Twitter @RevealMag for all your celeb, fashion and beauty news!