I think a helpful additional piece of information would be for a rating over the last 20 reviews (as well as a rating for all reviews). It takes 20 reviews to get a rating.  

So, why not have a additional piece of information to show how the past 20 reviews stack up against all? That way, if there is one bad review, for whatever reason, it eventually is dropped out of the "previous 20" rating, but still kept in the overall.  

If a lady is working hard at improving the time together with friends, then this additional rating piece would reflect that--one would not have to read the past 20 reviews to get an indication of what is going on