Privacy problem (see pic)

[whatisthisinhere]

My not so pleasant neighbour and her family, her visitors, etc. watch me from a second floor window every summer. I spent last summer trying to create a private space at the bottom of the garden which I did by making a woodland glade area and putting a bench behind a multi stemmed tree. But they can see me when I'm at the other side. They have an out building from where they watched me at the house end of my garden and I blocked their view with a crab apple and a parasol. I'm thinking of building a pergola with the help of a builder friend over the deck and adding a second one at the bottom of the garden.
Will this block their view from the window a little more?
I know this seems ridiculous, but they are awful and make comments and insult me, and have now moved in to my teen age daughter. I really need to block their view more fully.

As others have said, if they are harassing and insulting you and your children keep a record, a journal etc. Try to find out who your local PCSO is from the county police website & ask them to call on you. Mine was very helpful when my cul de sac had issues with an aggressive harassing tenant two doors up, on drugs. (He’s gone now!)
Meanwhile, ask a gardener type person to visit on the pretext you would get them to do some planting/build a pergola for you, and ask their advice about how to create privacy. They often have experience for this kind of thing. If you plant bamboo make sure it is not the invasive type. Ask at the garden centre to make sure!
It’s a shame you’re going thru this & I feel for you. Surely to God if you don’t respond they would get bored? It must be so boring for them to stand looking out of the window all the time. Have they nothing better to do? Would they insult you if you have friends (witnesses) over?
Your garden looks fantastic. Well done you, so far. Sounds as if you know a bit about plants, and garden-talk is such a good way to make friends.
Best of luck.

Experiment.

Stick two washing line props in, with a string running between them. Raise the height of the line and walk around seeing how much of their window is beneath the line, and from what points of the garden. You could hang a net from it. You'll be able to judge how high you need it to be, and how much shade it will cast.

Then your builder friend can help you construct a screen based on your experiment. As a PP says, you don't need the bottom to be screened, just the top. Grow something up the sides and into the trellis.

Report to the police online. Every time.

I reported it today. The teenage son has been shouting and threatening me again this afternoon.
I don't think much will come out of reporting it.

Can anyone recommend to me any long thin evergreen cedar like trees that don't grow too big and are not too spendy?
I've thought of an evergreen lollipop shape, but not sure I have the space for it, and I don't like how they look really, where as I think something lthin and uniform would help add structure

Plant a Leylandii right up against the boundary where it will block their view.

How about Juniper skyrocket? They don't grow superfast though so you would need to get a decent size one for it to be useful straight away.
www.rhs.org.uk/plants/53771/juniperus-scopulorum-skyrocket/details

Or thisThuja
www.rhs.org.uk/plants/75683/thuja-occidentalis-smaragd/details

It is also fairly slow growing.