I think people, who say your kitchen needs replacing think it looks dated. Maybe that’s because of the worktops. They’re quite dark and you’ve exacerbated that using black accessories. Maybe add some greenery or a few herbs in some light coloured pots (eg very light grey concrete). I’d go for the same sort of colours but make sure they aren’t dark so light to medium green. Maybe add a wood chopping board. Natural and woods are very in vogue.
I’m not sure you 100% really need blinds if you add the greenery I suggested. But you can make false ones. There are plenty of tutorials online to make false Roman blinds but that’s quite a lot of effort.
As for the rest of the house, I also think a lot of your house is very dark. The carpets, the furniture downstairs, most of the throws and rugs upstairs (although I see your ds has a much lighter one, which is much better), a lot of your curtains. Then in the 2 bedrooms you’ve contrasted the darkness with quite bold colours.
I would spend the your money on accessorising the downstairs and the main bedroom. As already said, a picture or mirror above the beds. Your living room cushions look tired and need replacing completely including the padding. You could review your colour scheme at the same time - I’d go for really light colours and the cream rug. If you want to add colour in the cushions, I’d go for light colours with a pop of colour.
But no dark colours. Just for example, see this cushion from dunelm. It’s light, there’s some colour there to break up the greys in the room and it complements your colours including your stool. And if you get a new pad, you may be able to get away with keeping the two pink ones So find a cushion you like, buy a couple and maybe a couple of others to compliment that cushion. Then add a plant or two, maybe a picture or mirror. I like mirrors better tbh. They make the room seem bigger and you don’t have the angst of choosing a picture you like.
Get some accessories you like for what is the dining room and a mirror above the dresser Be careful not to buy dark accessories as so much is dark already. The only exception I’d say having looked at Dunelm is a black bamboo lantern. Not for the dining room but maybe in the windowsill in your bedroom - see through rather than a block of colour.
I also would put the dining room back and the sofa inside the family room so you have the outside inside as it isn’t necessarily a family room. It could be a sun room and people with no kids could imagine themselves sitting in to enjoy a glass of wine.
The room I like best is your office. It looks very calm. Great colour combinations with the yellow shirt on the wall. I also think the master is ok but needs titivation. I agree to get rid of the fan, add some cushions and new curtains.
I’m a bit torn about the lilac bedroom. The rug and throw are too dark and the curtains aren’t great. But if you can get your main bedroom (including changing those curtains) and the downstairs right, some pictures and mirrors up and your house will look far better.