Legs too far apart?

Pose controls don't work for you? - The limits are usually set that you can move them together.
If you want to move / rotate them further you can change the limits or turn them off all together by clicking on the "toothed wheel" - icon in the upper right corner of the poseslider you want to use ("Side-Side" in your case). - Yeah, your caracter can turn her / his legs 360 degrees...
Other way would be to use character morphs in "Shaping" - tab.

Of course you could modify the characters rigging / bones as well but then you'd also have to adjust weight maps so geometry deforms correct. There are many and good tutorial videos on the DAZ website as well of others if you search a bit (it's a big theme).

Or just use translate tool after you mark one shin and move it and do the same with the other shin. Then legs are moved together aswell. - Probably the easiest solution.