In the given sentence the subject and the object of the verb is 'Mary'.
The reflexive pronoun and reflexive pronoun for singular first person 'I' is 'myself'. Thus option A in incorrect.
The reflexive pronoun for singular third person is 'himself','herself' or 'itself' according to the gender of the noun. In the given sentence the noun is a female. So, the reflexive pronoun used must be 'herself'.
Thus option E is the correct answer. Options B and C are incorrect.
'Oneself' is used when the subject of the sentence is 'one' or when the subject of the sentence is not mentioned. Thus option D is incorrect.