Knowing the answer to this question helps drastically narrow down the possibilities of shoot locations. And, there are actually a few locations that offer both "nature" and "urban"-ish feels, if you just can't decide between the two.
A few things to consider when choosing a location:
-Wardrobe: What you are wearing makes a difference. You want what you are wearing to blend well with your surroundings. So, if you plan on dressing your family in a very urban chic style, it probably wouldn't make sense to shoot in a field of wild flowers.
-The ages of your kids: Sometimes urban settings mean you will be on or near city streets. Of course, safety is always my priority, but with little kiddos, sometimes more quiet remote locations are sometimes better. College campuses. city parks, or state parks are also great places to shoot with littles, because they are more contained and controlled, so safety isn't as much of an issue.
-Pets: Do you plan to bring Fido to your shoot? If so, consider a location that is best for him. Often times, pets are already nervous and jumpy during family photos, so make sure you choose a location that won't add to your pet's anxiety.
-Distance from your home/Drive time: OK...it's no secret that getting photos made isn't everyone's favorite thing...and sometimes, certain family members can get a little cranky (I'm looking at you, Dads). If this might be someone in your fam, you may want to avoid long drives to your photo location. Long drives (especially for kids) typically aren't fun. Younger kiddos often fall asleep during drives. Plus - it gives any less-than-enthusiastic parties more time to sulk. So, by the time you arrive to the session, everyone is tired and maybe a little reluctant to participate. So, be sure to consider locations within 10-15 minutes of home if your family is prone to whining about family picture day. Although, I find that most anyone can be bought with ice cream. ;)
-Home Decor: I know...this one sounds like it's totally coming out of left field. BUT...hear me out. You are having family photos made to document your kids at a certain age. You may be having them taken for Christmas cards. Whatever reason you choose to get photos taken, my hope (and the hope of every photographer everywhere) is that you will print them and hang them on your walls! So...if your plan is to get a large canvas printed or make a gallery wall out of your images, you want those images to blend well with your home interior. So choose your photo background with that in mind.