体贴先生 standalone doesn't look right because it suggests that 体贴 is an adjective.

In the sentences  “她很体贴先生。” or "她是一个体贴先生的太太。", 体贴 is used as a verb.

So, 体贴 can't be used as an adjective but a verb.

体贴先生 standalone doesn't look right because it suggests that 体贴 is an adjective.

In the sentences  “她很体贴先生。” or "她是一个体贴先生的太太。", 体贴 is used as a verb.

So, 体贴 can't be used as an adjective but a verb.

P. S. 体贴 looks like an adjective in 她很体贴. But体贴先生 itself looks more like a verbal phrase without a subject, which suggests an incomplete sentence.