Ive just realized Percy calls Molly Mother a lot but with Arthur its Dad, not always but you see that appear more than mum.
I’ve always thought that Percy was never close with Molly. She may have favored him and while I think he wanted to make her proud and be seen as perfect I’d think he find it suffocating with her at times. With constantly being compared to his siblings, even if it was a good light for him I feel like that would add to his stress of having to be perfect.
I’m sure he loves Molly but I think it was far more difficult for Percy to fight with father than hurt his mother
I never noticed this, so of course, I had to go back and search, and you are absolutely right. There is not one instance in the entire series where Percy calls Molly 'mum' and yet there are many instances of him calling Arthur 'dad'.
This realization sent me down the rabbit hole, so I went back and analyzed all of Percy's interactions with Molly, and... there's literally no textual evidence that Percy was Molly's favorite.
We, as a fandom, tend to buy into this idea because of how upset Molly was at Percy disowning the family, but now that I'm looking back, I genuinely think she would have reacted the same way if any of the kids had left the way Percy did. In fact, I realized upon rereading that Molly's "love" of Percy was more like a love of Percy's prefect and Head Boy status.
Here is every interaction with Percy & Molly.
There is only one in Book 1:
“Can’t stay long, Mother,” he said. “I’m up front, the prefects have got two compartments to themselves —”
“Oh, are you a prefect, Percy?” said one of the twins, with an air of great surprise. “You should have said something, we had no idea.”
“Hang on, I think I remember him saying something about it,” said the other twin. “Once —”
“Or twice —”
“A minute —”
“All summer —”
“Oh, shut up,” said Percy the Prefect.
“How come Percy gets new robes, anyway?” said one of the twins.
“Because he’s a prefect,” said their mother fondly. “All right, dear, well, have a good term — send me an owl when you get there.”
She kissed Percy on the cheek and he left. Then she turned to the twins.
The kiss on the cheek is not indicative of any close bond, because we also see later on that:
Mrs. Weasley kissed all her children, then Hermione, and finally Harry. He was embarrassed, but really quite pleased, when she gave him an extra hug.
As for her excitement with Percy being a prefect? Here was her reaction to Ron being a prefect:
“His badge,” said Fred, with the air of getting the worst over quickly. “His lovely shiny new prefect’s badge.” Fred’s words took a moment to penetrate Mrs. Weasley’s preoccupation about pajamas.
“His . . . but . . . Ron, you’re not. . . ?”
Ron held up his badge.
Mrs. Weasley let out a shriek just like Hermione’s.
“I don’t believe it! I don’t believe it! Oh, Ron, how wonderful! A prefect! That’s everyone in the family!”
“What are Fred and I, next-door neighbors?” said George indignantly, as his mother pushed him aside and flung her arms around her youngest son.
She's excited that her child got recognition - and by extension, she got recognition. It had nothing special to do with Percy.
There are no interactions between Percy and Molly in Book 2, but we do have this conversation:
“Beds empty! No note! Car gone — could have crashed — out of my mind with worry — did you care? — never, as long as I’ve lived — you wait until your father gets home, we never had trouble like this from Bill or Charlie or Percy —”
“Perfect Percy,” muttered Fred.
“YOU COULD DO WITH TAKING A LEAF OUT OF PERCY’S BOOK!” yelled Mrs. Weasley, prodding a finger in Fred’s chest. “You could have died, you could have been seen, you could have lost your father his job —”
She mentions Bill & Charlie first, and she only focuses on Percy after Fred does.
There are two interactions between Percy and Molly in Book 3, one of which was Molly asking Percy to look out for Harry, which doesn't imply any sort of favoritism, and the other was:
“I said, that’s enough,” said Mrs. Weasley, depositing her shopping in an empty chair. “Hello, Harry, dear. I suppose you’ve heard our exciting news?” She pointed to the brand-new silver badge on Percy’s chest. “Second Head Boy in the family!” she said, swelling with pride.
Yet again, we see Molly more excited about the accomplishment of being Head Boy, and she is quick to point out that Percy is the second one in the Weasley family, because of course that's a status symbol.
There is only one interaction between Percy and Molly in Book 4, and it's not a positive one:
“Your father hasn’t had to go into the office on weekends since
the days of You-Know-Who,” she said. “They’re working him far
too hard. His dinner’s going to be ruined if he doesn’t come home
soon.”
“Well, Father feels he’s got to make up for his mistake at the
match, doesn’t he?” said Percy. “If truth be told, he was a tad unwise to make a public statement without clearing it with his Head of Department first —”
“Don’t you dare blame your father for what that wretched
Skeeter woman wrote!” said Mrs. Weasley, flaring up at once.
She's definitely not showing favoritism here - she doesn't even let Percy get away with saying a mildly offensive thing about Arthur.
In fact, in Book 4, when the whole Weasley clan returns from the disaster at the Quidditch World Cup, and Molly has been worried sick, she hugs Fred & George first - she doesn't even address Percy.
It isn't until Percy leaves the family that Molly focuses on him, and I really do think she would have done that for any of her children.
To summarize, there is no actual evidence to prove that Percy was Molly's favorite child - in fact, there's more evidence proving that he wasn't! 😱
So thank you for this comment, because it seriously made me reevaluate my thoughts and headcanons about their relationship, which was fun! 😊