Dividing A Cluster Of Norfolk Pines

Question

They are approx 15″ tall with 6 in a small pot.

Answer 1

You would need to check whether they are individual trees with separate crowns or just one or two crowns with several trunks arising. You wouldn't want to separate the trees coming from one crown or growing point.

If you have several separate crowns, you can divide those carefully, disturbing the roots as little as possible. Plant each crown in a separate container, with the new soil line the same as it was before.

https://www.gardeningknowhow.com/houseplants/norfolk-pine/norfolk-island-pine-care.htm