70s illustrated children's book about a witch who lives in the attic of an old house purchased by a single mother

Question

The plot as I remember it: A young boy and his mother move into an old house in the country (this could be set in England, not sure). I am unsure about the boy's name, but I believe his name is "Nicky" or something similar, and I don't recall if there was any reason given for his mother being single, such as being a widow, or divorced. They discover a short, frizzy-haired witch who lives in the house and isn't happy about them moving in, but they change her mind and make a cozy space for her in the attic, which she is happy with. She has a signature curse that she uses throughout the story, usually exclaimed at passersby: "rats, bats, and snakes' knees!" The mother starts some business (bakery, perhaps? Not sure) in the house and the witch becomes very helpful. At some point in the story, some burglars break into the house and when the witch confronts them, they put her headfirst into a barrel of flour. As they are pilfering things, she carefully peeks out from under the lid of the barrel and turns them into toads. The story ends happily with the witch enjoying her new pet toads, which she keeps in a small bird cage in her attic room.

I remember reading this book when my family moved into a house formerly owned by some friends of the family, and this book was left behind. I was about 7-8 years old, so it would not have been published later than 1978. It was hardcover, large format (at least larger than letter or A4 size, and formatted almost square), and not very thick, so it would be a short story. It was very well illustrated, with the witch's character drawn more cartoonishly with very small eyes and a large rounded nose, but everything else was drawn more normal.

It's just one of those things that nags at me in the back of my mind every once in a while and it bugs me that I can't remember the title. Thank you!

Answer 1

Possibly Old Black Witch by Wende and Harry Devlin, as per this answer about the TV adaptation.

A boy called Nicky and his mother are looking for a new place to live somewhere in New England. The mother wants to buy an old cottage with the idea of turning it into a tea room. At first, they have trouble finding a place, but finally they buy an old house that badly needs fixing up, not knowing that there is an old witch living there.

The witch (whom they call Old Black Witch, since she’s dressed all in black and sooty and doesn’t seem to have any other name) has been sleeping in the chimney of the house for about a hundred years, and they wake her the first time they try to start a fire in the fireplace.

....

Then, one night, a couple of burglars break in. Since Old Black Witch is kind of evil herself, she can’t really fault them for wanting to rob the place . . . until she suddenly realizes that they’re stealing from her, too, and uses her magic to fix the burglars for good and give herself the pet toads that she’s been wanting.