Summer term of y10 is pretty standard. We do it in y12 too.
Work experience is a legal requirement but schools aren’t given any financial or logistical support to make it happen. An average sized school would need 180 y10 placements every year, or more - to meet kids’ preferences wrt travel etc. I reckon it’d be best part of a full time member of staff if you wanted CP etc checking out.
I think the covid thing is tricky. Schools have to proceed with planning stuff. We can’t write off the possibility of enrichment activities in seven months’ time on the basis that they might not happen. However, a lot of things in the last year and a half have been called “work experience” but have been only tangentially so. A kid checking in at 9am Monday on a zoom call, being given a project brief, and then checking in once a day with their progress definitely counts. It might be possible for a freelancer to do something like that with her.