Clean, paying early tenant, got a cat, we found e-cigarettes

[Cali Skier]

Preamble:  We don't announce that we are the owners, we don't hide it, but it never comes up.  We have a logo and a company name for all our properties, we look like a business.  We sign the owner line on the lease, but nobody every notices.

We have nice middle class houses we rent. In our nicest house we have Tenants that pay 2 weeks early, been there for about 4 months. They are friendly tenants, They call us immediately when there is a problem, and every time either of us is over there, the house is very clean and there are no odors... They came in with a dog, told us about the dog, paid a deposit and fee for the dog.

We were over there for a problem recently and noticed two things. A cat, and a pack of e-cigarettes on the counter. We have a very hard core policy on smoking / vaping, screen shots below... The cat is not on the lease, and we have strict rules about that.

They indicated that an older child moved in with them temporarily, trying to figure out a housing situation. That child brought the cat. The e-cigarettes, we are not sure if its this child and have not addressed that yet.  

I want to stay professional on this...  e-cigarettes on a counter does not mean they are being used on the property, its assumed though.

I am thinking this is the play... Tell the parrents, that the child needs to be added to the lease, and have that child sign all the same documents, and pay for a deposit and pet fee for the cat.  Once he moves out he can have his cat deposit back if we do not see any damanges or smells.  That's the cat.  

For the e-cigs....With the other documents, new child will sign the no smoking / vaping addendum, that might be a good way to address anything without saying "hey I saw a pack of e-ciggeretts on the counter".  Treating this child like we treat everyone, as we hand the document to sign: "And this is the no smoking addendum, just be aware, dont allow anyone on the property to smoke here, inside or outside, its impossible to get the smell out of the house" 

How would you approach this?