Mellisa's accent is NOT from New England
According to the bio on her website, Mellisa and her family are from Virginia. I'm from a nearby state and her accent doesn't sound Virginian to me - and definitely not New England either. I did find an old recording of her speaking and she has a little bit of the accent there. Most notably, she pronounces the word "whimsy" very weirdly.
I don't know if she's even lived in Maine. I assumed she must have some connection to there because she had a lobster themed restaurant in Portland, but it was Portland Oregon not Portland Maine.
I would say Mellisa has a small speech impediment or difficulty pronouncing words. It seems to get worse when she's nervous or under pressure.
Absolutely no hate for people with any sort of speech difficulty. I thought it makes her a more interesting character because she rarely shows any sort of vulnerability or something others could perceive as a weakness. I didn't like her terribly much but it was more so for all the complaints other people were getting credit for her work, as if winning Chef of the Day was actually being scored or formally counted for something.