2006 Civic

This one will be for the mom, and she'll only be driving it on the weekends, so would insurance be cheaper than the regular stuff? This is how we're currently insured:

2004 Honda CR-V - Dad
2005 Honda Civic - Mom
1987 Toyota Cressida - Me

So what am I supposed to tell them? That my mom likes to drive a newer Civic on the weekends?