Doesn't it only sound when cats are near?
How often does it sound?
I presume you are not there most of the day?
That isn't a police matter. They are right. That is one for Environmental Health as it is a noise nuisance potentially.
They will tell you to complete a noise diary for 28 days. If that is completed they will investigate.
If they find a case to answer they will seek a noise abatement notice breach of which is an offence that they can prosecute.
The noise does have to be more than would reasonably be expected. She is entitled to use cat deterrent methods and everybody makes a degree of noise.
Can I clarify anything for you?
There is no way of dealing with a noise nuisance by means of emergency Im afraid.
No. This is not child above.
It is a noise nuisance maybe.
Not every nuisance amounts to abuse.
If she breaches a noise abatement notice she can be prosecuted for that.
All the best.
You don't need to do anything else at all except rate my answer.