My old 6s iPhone is used by my husband and received a new SIM card, both phones are with Consumer Cellular. The 6s that my husband now uses, still under my name, does not do all things incl. 'Siree" What do I do?

You have to read -> this Apple article: What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch

What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support

Then you have to remove the iPhone from your account, see this Apple article:

Check your Apple ID device list to see where you're signed in

Check your Apple ID device list to see where you're signed in - Apple Support

Then your husband can sign in with his Apple ID.

Siri availability, features and commands vary by language, country and region. Find out which Siri features are supported in your country or region.