This is initially a bit tricky to navigate. Once Upon A Time is clearly more family friendly with its fantasy sequences and glitter but it also has very dark moments that are quite unapologetic (I'm including the "battle of the better mother" and twisted alliances aspect in this too). Grimm, on the other hand, is a procedural, complete with crimes, more-than-moderate crime scene visuals and brought-to-life monsters that I don't think little kids should see but the approach is often comedic and it's clearly a "catch the bad guys-save the good guys" show that kids have an easier time understanding.
Snow White and the Huntsman? Clearly teen+ with a largely dark overtone. Mirror Mirror on the other end of the spectrum is going for highly stylized comedic family fun.*
But in our immediate future we have SyFy's Neverland, airing December 4th & 5th for a two-night special event - apparently a 'prequel' to the Peter Pan and Neverland stories we're familiar with. Is this family fodder? After all SyFy isn't Hallmark or ABC/Disney and have a better reputation for the dark rather than the light.
website and marketing for Neverland are certainly aimed toward family but, as fairy tale enthusiasts who know what fairy tales are capable of exploring, it's important not to assume.
Neverland has attracted a stellar cast and has some seriously nice production and effects work. This alone says how much SyFy has developed in their programming. With Neverland looking to be a good viewing pick for the average family it's still worth preparing oneself ahead of time, just in case there are little people about - humans in your family, that is. ;) [If that ginormous and scary-looking crocodile does take Hook's hand off on-screen or Tink does get viciously-murderous I want to be there to cover my kid's eyes or make a dive for the remote - whatever seems most prudent.] There are a number of trailers out already which give a different emphasis on the story's aspects. The one below is my favorite:
This article HERE has made an attempt to summarize things for people wanting to know. Unfortunately their rating system is a little misleading at a glance. Using apples instead of stars makes it seem like the series are being rated overall as opposed to the compatibility with family viewing time but nevertheless it's worth a read.
Note: The following is a tangent but one I feel is appropriate for this topic. You may want to grab your thinking cap...
On the subject of "family friendly" I recently read an interesting on the Told This Time fairy tale community website, discussing an interview with Jack Zipes on the topic "Are Dark Fairy Tales More Authentic?". A few comments down the discussion begins to focus on whether or not we should expose children to 'dark' things and how appropriate many of the ideas in fairy tales really are.
Here's a quote from one of rave_blue's comments to get you thinking:
Real fairy tales, those traditional tales from Europe and Asia and indeed even America were often very dark to modern readers but then, we live in a world of light. Darkness can be banished with the flip of a switch but our ancestors lived in a very different world. Theirs was a world where darkness closed around them with all the menacing threat of the bogeymen they believed haunted the wilderness. So for them a "dark" fairy tale wasn't really dark at all because it was a perfect mirror for the real world surrounding them.
A child dying startles modern sensibilities but child mortality was so commonplace to our ancestors that it was taken in stride. Sure they mourned the death of a child but that mourning was not mingled with a sense of injustice the way it is today. Children died, it was a fact. People were maimed in surprisingly large numbers losing limbs in simple tasks. Wild animals stalked the forest. Robbers lurked behind trees ready to kill for a little coin. Darkness was not psychological the way so many modern interpreters would have us believe. It was both literal and symbolic because for the people who were listening to them when they were new it was the way of the world.
While most of us are privileged to not live in a society that must deal daily with such realities, we nevertheless have our own "wolves, maimings and darkness" so it's no coincidence that a familiarity with fairy tales is still proving to be one of the best defenses against them. The harder question, as I see it is how much is too much and what contexts are appropriate for different ages/maturities? Once you see something you can't simply 'unsee' it but parental response to the unfortunate and unexpected** is an additional key to children's coping mechanisms too.
I should add a disclaimer: if your family is anything like mine, being very familiar with fairy tales of all kinds and on monster-friendly side, it's very likely you'll take the chance and sit down with your kids just to check out that giant crocodilia and watch them nod wisely at just how devious fairies really are. That said, I'm going to make my pot of cocoa ahead of time and keep it in the living room with me. ;)
*In the same vein of family friendly comparison, Lily Collins (playing Snow White in Mirror Mirror) was interviewed on the two movie versions of Snow White - something she has the inside track on, as she apparently auditioned for both Snow Whites. You can read it HERE.
**eg. Whoever hacked the Sesame Street YouTube channel a few weeks back and uploaded a graphic porn video in place of a Cookie Monster clip deserves punishment by law well beyond a fine.