Thanks to all of you for your suggestions and help. I finally hired an IT expert. It took him an hour and a half of patient, dogged work to finally transfer my RM4 database into the new, empty RM7 on my new Mac. Apparently Parallels and Windows 7 were putting a lot of drag on my older Mac, and Windows 7 or RM4 would crash time after time. He finally was able to drag my database onto his own Google Drive, then opened his Drive on my new computer and opened the database file.
Only one snag: My photos show up as thumbnails in RM7, and I can't fully open them. On RM7, there is an option to back up with media, but on RM4, we saw no option to do that. It's not the end of the world. I've already used them in a book I published with RM4.
I guess I can move each photo into RM7 as new photos, from my Mac photos folder. Any other suggestions??
I'm very excited to work with RM7 on Mac!!!