Hi, OP -
I spent a few years organising Study Abroad for my School - at my (large) uni, most Schools have their own Study Abroad academic officer. What I say is true at my uni but I think most of it applies across the UK.
You typically have to be registered at your home campus for the entirety of your final year. In our School and many others throughout the UK, it is difficult or impossible to replicate necessary Year 2 courses overseas. So in practice, the only students we can send abroad are those in Y3 of a four year degree programme. Check to see if that is true for your DD or if she can go during Y2 of a three year programme.
I don’t know how fees to the EU will work under the Turing programme, replacing Erasmus. Home students on other international placements pay only their usual fees. In fact, when I was organising placements, Home students on non-EU placements for a full year got a substantial discount on the regular Home tuition fees, to help offset travel and other costs. Again, I don’t know if this still applies.
On some placements students have the option to live in residence halls, on others they do not. Medical insurance is a necessity and the cost varies by destination. The uni should have a Study Abroad office to deal with this kind of thing and to provide pastoral care. On the academic side, my role was to help students select courses that would provide good background for Y4, to help them adjust to the different teaching and learning styles they would encounter, etc. of course there was some overlap regarding pastoral support.
I also took the lead in converting their marks back to the British system. All but one person was within one degree class overseas of their Y2 average mark. More went up than down. Many said the greater term time demands in Australia, NZ and North America made them more organised and that Y4 back in the UK went better for this. Most students feel that both the mere fact of having been abroad, as a CV entry, and the skills they acquired from this, are enormous assets to their lives. Sorry this is so long!