SOLVED!: a boy babysitted by his neighbor (whom he hates) for a weekend [s]

[Veronica]

I remeber that it was a little boy who was trying to use voodoo magic on this neighbor that was supposed to take care of him (and maybe a few siblings?)for a weekend while his mother is gone. She makes them eat disgusting food and at one point, for some reason, i remember the women being bed-bound.
definitely a younger kid's book, very thin
front cover is a dark blue with a kid holding a flashlight

[MB (What she read)]

I think this might be Mrs Coverlet's Magicians.

[Veronica]

yes it is, thank you!

[MB (What she read)]

Yay!