Hi. If you plan on keeping your bedding as it is, then I suggest you pick up a very light lavender from it for the ceiling -- something like the colour below.

I'd suggest you have a look through the photos section on Houzz - or there's quite a few good articles on how to decorate :) maybe both you & your wife could save pictures to an ideabook with a few words on what it is you like about each one, and it'll give you more of an idea of what type of things you like? I think colour-wise, turquoise and peach can go together really well - maybe a warm cream colour on the walls & pops of turquoise and peach in the form of throw cushions etc.? Again, just searching on Houzz can give you some great ideas - just literally searching 'turquoise and peach' brings up quite a lot of pictures :) to get you started I've just picked out a few which I personally think work well :)

Basics first, please get rid of any plastic furniture like that chair. secondly all table tops need to be cleared of little mirrors, table clocks etc. just place three most loved items of your choice ! Arrangement can also be improved the table could come on the side and bed could be centred a bit better (along the window behind it). Walls can be painted a neutral shade like light beige with a rug of your choice on the floor (contrasting- like red so that the pink curtains could go with it)If you could change the curtains then the best option would be to pick a solid colour of your choice and a matching rug (blue, red etc whichever is your fav colour but please avoid printed cutrains)

8.75 would be fine to it's only a difference of 3 inches.. Are you going to do up lighting? In the second picture that ceiling is really set up for it and that opens up a lot of options on your finishes and textures on the ceiling.