Advice on posing kids & teens

[Not4you]

As a favour for my sister-in-law, I'm going to be taking pictures of the children in her extended family this weekend.

There will be:
a 6 month old boy
a 3 yr old girl
a 6 yr old girl
a 15 yr old girl
a 16 yr old boy

Now I'm just not sure what I can do with them that will look natural and candid but that will not make some feel out of place. If I have the younger ones playing with the baby, the two older ones will seem out of place to me. I'm looking for ideas and example of group compositions that could work with this range of ages.

Weather here lately has been snow so outdoor options may be somewhat limited since there is a 6 month old in the group ...

FYI - I have less than one year experience with non-PnS photography. My gear is rebel XTi, rented Speedlight 580, nifty fifty, 28-80mm and 75-300mm.

Any and all tips, suggestions, example and advice is greatly appreciated.

Thanks POTN.

[onedownfiveup]

I will tell you this, get the pictures taken quickly and early on in the session. They get tired and worn out fast! I just did a session with my cousin's family and her friend's family and they both had kids 4 and 8 months.

[Not4you]

Wow that was some GREAT advice. I did the shots today and you were not kidding! I had a window of about 20 minutes before the littlest one was crying, the middle ones lost interest and the older ones were off facebooking on their blackberries. But I did manage to get some nice lighting with the 580EX II that I rented and a few keepers!