I think 5 meets is a pretty normal full season for many level 5s, so if the skills are there with good form and confidence, I don't see a problem with the move. Especially considering she can always repeat level 6 in the fall if the level 7 skills just don't come together in time.
My thoughts on mid-season move-ups are kind of all over the place based on the individual child. For a child who has the skills and who will be motivated even more by lower scores/placements in a higher level than consistently placing in the lower level, I think it can be a beneficial move. As well as for older kids, girls who struggle with the rigidity of compulsory routines, those kinds of circumstances. I would be against it in situations where the child had nagging fear issues, would be better served with a few more incredibly successful meets in terms of confidence building, or who would be more stressed out by the more rapid progression than benefit from it.
How does your dd feel about the move? If she is all for it and her coaches recommended it, I don't think you should worry too much.