What retirement visa should my husband apply for in Thailand, and what visas are available for my daughter and me as dependents?

The best advice is go and speak directly with the Thai Embassy in London or get in touch with a company called Siam Legal they will give you all the advice you need

Let your husband get his VISA. Go get a 5 year DTV Visa and get your kid as a dependant. You should be fine for 5 years.

Hello, I'm not sure you would get a dependant visa (I'm not an expert by any means, this is just what I have read), as the criteria i found i have pasted below. May be worthwhile contacting specialists suck as Siam Legal to enquire about option and how the can assist you.

NON-IMMIGRANT VISA-O (SPOUSE/DEPENDENT)

Non-Immigrant Visa-O may be granted to applicants who

lawfully married to a Thai citizen or lawful parents of the Thai children.

Accompany foreign spouse/parent who works in Thailand

Accompany foreign dependent who studies in Thailand

A couple of alternatives

If your husband qualifies for the LTR Wealthy Pensioner visa both you and his daughter could be his dependants.

If your daughter will attend school she could get an ED visa and you a guardian visa

The only retirement visa that MIGHT allow you to be a dependent will be the non-OA visa. This one has higher requirements than the non-O that most people use, including a health certificate, criminal background check, and mandatory health insurance. You would need to check with your embassy to see if they are willing to do it if your husband gets a non-OA or not.

No embassy sells the trailing spouse dependent visa anymore if the primary person gets a non-O visa. And trailing spouse is not available inside of Thailand either.