Premise: "A young woman wearing a white dress with a blue towel in her lap is having her hair dried by another woman used a hair dryer."\nHypothesis: "A lady's hair is wet."\nDo we know that the hypothesis entailed by the premise?
Let's be accurate as possible and think first.
yes
The lady is having her hair dried so her hair must be wet.

.

So, the answer is yes