What can I do about my neighbour?

[Christmascrackerxo]

I live on a fairly nice street in a terraced house. My next door neighbour has recently started having ‘friends’ over. They shout and talk so loud all through the night till 6am. She has people coming and going constantly and this evening as I was leaving my house there was a bag and a can of cider outside my front door. An intoxicated man appeared from the ally way which leads to my back garden asking if I’d seen the neighbour. This isn’t the first random man that has been in my garden trying to gain access to her garden by hopping over my fence. I have a son and honestly I’m scared and if my son saw a random man in our garden he would be terrified. Her car window has recently been smashed during the night so I imagine these ‘friends’ are not safe people to be lingering around. What can I do? I don’t want want to say anything as I’m worried my car will be vandalised. If I contact the police I’m not sure they will do anything plus they will know it’s me who has reported.

Owned or rented property?

My suggestion might be that it's a safeguarding issue so landlords and the Police

You do need to call the police. See if you can find the local neighbourhood team and ask for a chat with one of them to see what help they might be able to offer, without causing friction.

She can't contact the police because her neighbours are talking loud lol

If you catch someone in your garden, then phone the police ofc. What's the situation of fence jumping, can you block it off? Is it a communal alley or just your access?

Has your neighbour been cuckooed?
I would be tempted to ask the police to check this out.

I would go gently and ask the neighbour if she is being intimidated by the people who are calling as you are. Who really enjoys loud drunk people in their actual home ? Tell her what you have witnessed and diary all incidents - how long , who etc as evidence if you have to take another approach. I would express how stressed you are and give her a chance to at least give her take. Failing this and more of the same then you would have to take action .