Mould - please tell me I can fix this

[Nerf]

Nothing has changed except for DG two or three years ago. About three months ago, dd's room (tiny) had mould all above the window. Tonight it's returned all above the window, on the window, and along the nearest wa sutshut?
Please tell me this is because she always has her door and window shit? And I can fix this?

Shut!

the commonest cause of condensation, damp and mould in British homes is wet washing draped around the house and over radiators. Do you?

Followed by persistent breathing and insufficient ventilation. Do your windows have trickle vents?

Do you have an effective extractor fan in your bathroom?

It's lack of ventilation. I would suggest cleaning it with a mould cleaner (ronseal is good) and repainting with an anti mould paint.

No trickle vents, but yes to those little stoppers that make the window open a teeny bit when you push it open.

No wet washing at all except for on a dryer downstairs - no mould there

No fan but bathroom window always open

Ds room has developed mould recently. She usually has the window shut (fear of spiders) and the door shut (fear of little brothers)

Sorry dd's room.

So I might be able to stop it happening again if I make her open the window and door?

I've cleaned with bleach and water for now and have ordered some mould apart.

Spray not apart

opening the windows every morning after throwing back the covers will prevent dampness accumulating.

The house fairies can close them after making the bed.

It is possible to add trickle vents to existing windows, but not as easy as before they are fitted.

Thank you!

Will leaving them open on the vent lock things be the same as the trickle vents?

Tell me this will be fine

yes, but I expect she will shut them when you're not looking.

Eeek! Actually her fear of spiders is battling her ocd (genuine dx) over the mould. She's already chucked out all the books.
The room is really small and she leaves piles of stuff up there.
I've just bought loads on amazon in a bid to find something to help

if necessary, you could have a builder bore a vent in the wall (preferably high up) like you would for an extractor fan, but with a plastic vent on the inside (includes insect screen) and no fan needed. Modern equivalent of an air brick.

That's a brilliant idea. Thank you.

we had a similar problem in a flat we rented. We got a small dehumidifier and ran it for most of Winter. It sorted the mould out. Just had to remember to empty it.

Thank you did you use anything else?