Unfortunately I think PP nailed it - it's been extended beyond it's capability really (sorry) and has probably exceeded a realistic ceiling for that property in that street.
In reality it's a 3-bed with a study which is still really desirable, but there are innate features which means you're still not going to be hitting the max values even as a 3 bed semi.
Your kitchen and lounge are lovely, bright and nicely done, so is the master suite. I love the paper in the green bedroom.
You could swap the cot into the room with the bulkhead, get rid of the desk and put a queen/double in the green room with side tables (extra expense I know). Put middle child in current nursery & hide the clothes rail. Declutter the shower. Take the empty planters off the drive and garden.
But it's will come down to price & a tough market. Lovely houses are sitting on the market here because they all feel massively overpriced, while people see their disposable income dropping week on week. Stamp duty is wild. Rach Reeves hinting at dicking about with that helps nothing.
Good luck 🤞🏼