I also work as a TA at a primary school in the UK. Like many posters said above, you can see children writing like that in reception (and would be an able child given the correct use of punctuation and spelling), or in Year 1 or even Year 2 (but in this case it would be a lower Year 2). In extreme cases where children have learning difficulties you can see children who are in KS2 writing like that.
Based on your posts, it seems your DD is a keen learner, so I wouldn't worry too much even if you decided to come back to the UK in a few years. If she is a little behind she will catch up quickly given that she seems like an able and capable child. Follow her lead, if she likes writing you can provide opportunities through playing, have paper and pencils/crayons available for her to use, write letters, cards, shopping lists, books for her toys, etc. Read with her at home, and again, follow her lead.
I taught my two DS to read in my native language before they started reception. My first one learned to read in English with phonics in Reception and was a free reader by the end of Year 1. My second one was so keen to learn to read in English in addition to reading in his first language that I bought phonics books and he picked up really quickly and could read fluently in both languages when he started Reception. But the problem with DS2 was comprehension as he only started learning English when he was 3, and there was a lot of vocabulary that he could read using phonics but didn't know what it meant. But he picked it up very quickly and by Year 1 he was a year ahead of what his average level should have been.