I think Zaccaro is more fun but she may find Singapore engaging as well. DS6 sure did. Last year at one point he did math problems instead of reading before bed. Go figure:)
I like both Zaccaro and Singapore. We homeschool and use Singapore. My plan is to spend the rest of the school year doing Zaccaro after we finish our current workbook (5A) and CWF.
I think the main advantage of Zaccaro is that it covers lots of different topics which may be more appealing.
Fred is a fun read. I wouldn't use it as a standalone curriculum but it's a really nice supplement.
