My clients Filemaker 6 file takes a long time to open now. At least a full 60 seconds. It seems like it's frozen, but if you give it long enough to open, it eventually does. Could this be caused by too many related records? It doesn't seem like there is that much data in her db. She's only got about 500 records but each one has quite a few related records.

Try clearing the temp files on her machine.

I encountered a similar problem. It was solved after I had simplified the numerous variants of the file references (Define -> file references) that were created by FM 7 after the conversion from FM 6.

Oddly enough, all I did was to rename one of the related files (the one that seemed to be hanging things up), and made a new relationship to it and now everything works great!

I'm not sure why, but I'm glad I found the solution.