She sounds like she is on the dyslexic spectrum. Children with dyslexic tendencies often get the order of letters mixed up when spelling. Yes I would suggest teaching her the digraphs cursively, as well as allowing her to practise 'writing' them in sand, in the air, using her finger to trace on different textures e.g. a carpet tile, sandpaper etc. Also give her a 'sound' mat that she can refer to (have a look on communication4all) Cursive writing is thought to help dyslexic learners as their motor memory is stimulated by the flow of writing. I don't think you should only teach her the digraphs cursively, she should be taught to join all her letters. She also needs to develop her ability to proof read her own work and self correct. This is not easy for dyslexic learners, but is a skill that they do need to develop. To start with you could help her by highlighting words together. You may find though that even if you do all the above she will still occasionally get the letters mixed up. It is the way the brain processes language differently in the dyslexic brain. I'm sure others will be along to suggest other ideas too, but I hope some of this has been helpful.