In the alternate universe, Mia is very similar however dates Sam's replacement instead, Sammy.
Before Season 1
Mia and Sam made out at Mia's house while watching The Exorcist. Mia's dad caught them and wasn't happy.
Mia went to the local magic shop, Arcane Lane, seeking friendship bracelets. While speaking with the owner, the school's goth Felix Ferne went into the back room, but was chased out by the owner, Phoebe Hartley.
As Mia was walking through school, Sam found her and promised to be a better guy. However, Sam had to leave after Felix called. Ellen confronted Mia, saying they had to find out what the boys were up to.
Nowhere Boys: The Book of Shadows
Mia watched Sam at a skating contest, but because he used his powers she wasn't impressed.
The next day, Sam pulled Mia into an empty classroom. She was amused to find him with a monobrow, but agreed to help him. When he said his fans can't see him like this, she refused to help and took a photo of him for Instagram.
She, Ellen and Viv walked down the corridor, complaning about how the boys and their powers. A strange girl named Tegan brushed past them and they made fun of her. Ellen became so mad at Felix's selfishness on not giving her her own powers that a cloud formed above her head, which Mia informed Ellen about. They sat out of sight and Ellen helped them try to find out what element Viv and Mia belonged to. Tegan arrived, and they shortly realised that they are the four elements and just needed a book of shadows (Mia was air). They play a prank on Sam using the Earth element, but he blames Jake. The four girls walked around school, playing pranks on numerous people. During this, Viv and Mia were impressed by Tegan, thinking her as cool, confusing Ellen. Suddenly, thousands of bees swarmed the footy field, attacking Tegan, much to Mia, Ellen and Viv's shock.
Later, the girls celebrated Tegan's birthday several times, due to her 'having a lot to make up for'. Mia and Viv were fascinated and almost obsessed by Tegan, but Ellen was still wondering why.
The next day, the four girls approached the four boys on the street. They attempted to cast a spell and defeat Tegan, but she stopped them and sent a gust of wind to Felix, knocking him over. She was concerned, but Mia and Viv told her he deserved it. Mia approached Sam, and ignored his warnings of Tegan's danger, and she knocked him over using her air power. The boys tricked Tegan and she got mad at the girls. Ellen (really on the boys' side) convinced her to dump Mia and Viv. Tegan wiped their powers, leaving Mia and Viv very upset, and back to their normal selves.
Later, chaos was unleashed on Bremin and many people were possessed. After the boys sacrified their powers and stopped Tegan, they, Ellen and Viv walked home. Mia, riding a bike, saw Sam and implied she wanted to get back together with him.