Disney Infinity Fans

I was researching one of the Star Wars figures called Sabine Wren.
Since I wasn't able to find definitive information on what playset she belongs to, I am asking the question here:

According to the wikia, she does not have a native playset, but can be unlocked to play in all 3.
Can someone clarify what this means?

The way I am interpreting it, you need to find her Unlock Coin before you can play her at all in any playset.
I find that unusual, since all figures can be played in at least one playset.
If the information is accurate, it means you need to use another playable figure and the specific playset (I think it is the Star Wars trilogy one) to unlock her.

Can anyone give more precise details on this subject?

You are correct. In order to use a Star Wars character not native to the playset, a character coin must be found first. Each character has their own coin.

A Luke Skywalker coin in the Twilight of the Republic playset will only unlock Luke for that playset. Sabine would have two coins as of now, one for the Twilight of the Republic playset and one for the Rise Against the Empire playset.

Hope this helps!

Edit:

This also means you would need a character from the native playset to collect the coins for non-native characters.