@Deborah794 You say they have rated you 5*s, but I didn't think it was possible to only rate but leave the written review field blank. Perhaps that's only true for host reviews.
I have seen comments here from hosts with guest books saying that those guests end up not leaving a public review, but it's not necessarily something that's overall true.
I'd maybe put a page in the front of the guest book letting guests know that you're really appreciative of their comments there, but that if they can find the time to also leave a public review before the 14 day review period is over, you would be very grateful. That good public written reviews help guests to be readily accepted in the future and hosts to get more bookings.