Adopted kittens urinating - help!

[JustDrive]

We adopted 2 kittens aged 8 and 10 months. We've only had them since last Friday. Both girls and lovely natures, really pretty, we love them so much already....
BUT!
The peeing, is it normal? They don't seem stressed out, they have and can use their litter tray, but they've been peeing outside the box.

One did a poo in the hall on Monday but has used the tray since.

The other peed on my bed while I was laying in it?!
And this morning one has gone on the sofa, not sure which one. The smell is awful.
I have ordered some feliway spray and a plug in. I have got another litter tray so now there are 2 available (they only had 1 at previous home) is there anything else I can do?! Other than not let them out my sight!

They are being spayed next week and will start going outside within the next 3 weeks, will this help?!

It should help - as will the extra litter tray.

Goodness, they should have been spayed months ago. Have they had all of their shots?

(Did they know each other and get on before they came to you?)

Thanks cozie - they did live together previously and get on really well together, playing, grooming and cuddling most of the time.
They were being kept as indoor cats so no shots, no spaying, no flea/worm treatment. They had their first injection today and health check with the vet and will be spayed next week. So expensive!

Vet advised feliway and I'm really hoping it works as the smell is awful!
Other than the toileting I have no problems with them at all, they're gorgeous.

I had some toilet issues in the early days of my two. An extra tray and a bit of time solved it. I think it can be a bit of stress, a bit of 'marking', and a bit of plain confusion.

If they are using the tray sometimes then that's a good sign. Are you using the same litter they had before? Scoop out poos and wees as often as you can, and maybe make sure there's enough depth of litter for them to dig properly? Also, maybe make sure the trays are in private-ish locations. Mine have never minded about this (as my guests can attest) but I know some cats do.