The correct option is
D a little
It is clear from the sentence that the answer must be an adjective. Further, the sentence indicates that Helen has a certain amount of money. Thus, the answer must be an adjective of quantity.
Option A is incorrect. 'Any' is generally used in a negative or interrogative sentence. It does not fit well wit the object 'money' in this case.
Option B is correct. 'a little' is an adjective of quantity that fits well with the object 'money'. Further, the word 'only' indicates that the amount of money is small. Thus, 'a little' justifies the presence of 'only' in the sentence.
Option C is incorrect. 'no' cannot be used as it does not justify the presence of 'only'. 'only' indicates that the amount of money that Helen has is small but existent and 'no' contradicts that.
Option D is incorrect. 'few' cannot be used as it is only used for plural objects. Also, it is generally used for countable objects and 'money' is not one of them. Thus, it does not fit well with 'money'.