Agree with all pps regarding charts, centile lines, development.
One other thing I notice though
3/4 punnet of 250g strawberry
three quarters of a punnet of strawberries? so roughly 180g of strawberries? I'm going to guess (based on the pack DS finished off this week) this is about 10 strawberries (although depends on size of course), in one sitting, for dinner. That's a LOT of strawberries for a little girl.
Fruit is great of course, and you feel she is small and has a limited diet so you want her to eat as much as possible, I understand, and strawberries are healthy, but this is a huge portion. Even if it was "3 or 4 strawberries" from a punnet it would be quite a big portion for a toddler. A toddler portion size is about the size of their fist, often this is a quarter of a fruit but with strawberries I'd say probably 1 fruit. I always let my DS have more than his 'quota' of 2 portions of fruit per day too (for toddler it's 2 of fruit, 2 of veg), he would have blown a fuse if I'd given him quarter of a banana rather than the whole thing...but we did also have a short time when I put my foot down on fruit. It only took 2 to 3 days, the first was the worst, lots of frustrated crying in my arms when I wouldn't let him have more fruit than I had served, I explained he'd had enough fruit and if he was hungry he could have something else.
Might be worth thinking about. If she's full of strawberries she may not be hungry enough for chicken or fritata or any of the other lovely food you make.
A great tip I had from BWers when mine wouldn't eat protein - offer it at breakfast. I was nervous to change his breakfast in any way as it was so habitual, same muesli balls every day. But I tried the tip, cooked an omelet for breakfast and he ate the LOT without so much as a 'where's my muesli'. He'd been refusing omelet at lunch and dinner for months (but had eaten egg from 6 months so I knew it wasn't a true dislike more of a not want), from then on I served egg every morning and the rest of the day I could relax about protein intake, still served a small portion of meat and fish to expose him but not be so worried if he didn't eat them. I would try it. With protein, with veggies, with new foods. It isn't about forcing the new foods onto them but catching them when they are more willing to take it (and not so full of fruit).
Oh and mine is not on the 4th centile, more like 25th to 50th but still petite. He is 4yo his clothes are 2-3 years. At 2 yo he fit in 3-6 month trousers to wear as shorts.