Trapped inside their family cottage, a group of detached siblings must battle a vengeful witch and break a centuries old curse on their family.

“Trapped inside their family cottage, a group of detached siblings must battle a vengeful witch and break a centuries old curse on their family.”

This logline lacks focus. To start with, “trapped inside their family cottage” should be the inciting incident. Does the witch trap them there? Describe a specific, singular event. The logline also presents two objective goals, to battle the witch and to break a curse. ?I assume that by defeating the witch they break the curse, is that the case?
While having multiple protagonists is fine(I suggest no more than three who are the focus, even if there are more characters) what is special about them? What skills do they have which allow them to fight a witch, and have a chance of winning? Do they have magic? Is this witch the one who cursed their family? Is she a descendant?
And the most important thing, what exactly is your hook? This doesn’t sound very different from other horror movies. What’s unique about yours?
For general information on forming a logline, check Formula tab at the top of the page.

Here’s an example:?After a vengeful witch kills their parents, three estranged siblings must use their limited witch hunting skills to kill the witch who placed an old curse on their family. (29 words)

I hope this helps.