Can my wife work remotely in Thailand on a DTV visa as my dependent?

Yes no problem all DTVs are the same.

In my humble opinion, this is allowed. It already says on every DTV e-visa that employment is prohibited (“Remarks: Employment Prohibited”). The remote-working subcategory only serves - like all other subcategories - the right to stay in the country. It does not make a clear statement like: with this you are allowed / not allowed to do remote work.

In the case of the remote-working subcategory the statement is: Your right of stay is based on remote work. Even if someone enjoys the right of stay under a different subcategory ("my dependent", "Soft Power"), remote work is not necessarily prohibited.

Remote work is, in this view, always not prohibited or even tolerated (maybe welcomed) as long as it does not match the Thai definition of employment or business (essentially work done for Thai or Asian customers that could also be done by a Thai person).

Non-binding opinion of a non-lawyer with a sense of legal understanding.

Yes

She is dependent on you, not allowed to work.

IF she want to work in Thailand she needs to apply for the purpose Workcation.

You can not mix and match different requirements to different purpose of usage of the visa.