Based on my reading of McHugh and Callan Moral Theology, I believe her mockingly use of the Name of God constitutes non-heretical external blasphemy:
889. Internal blasphemy does not differ from unbelief or disrespect for God. We are concerned here, therefore, only with external blasphemy, which is contrary to the external profession of faith. External blasphemy is opposed to faith either directly (by denying what is of faith) or indirectly (by showing disrespect to what is of faith), and hence it is either heretical or non-heretical.(a) Heretical blasphemy affirms about God something false, or denies about Him something true. The false affirmation is made directly, when some created imperfection is attributed to God, or indirectly, when some divine perfection is attributed to a creature. Example: It is heretical blasphemy to affirm that God is a tyrant or the cause of sin, or that man is able to overcome God. It is also heretical blasphemy to deny that God is able to perform miracles, that His testimony is true, etc.
(b) Non-heretical blasphemy affirms or denies something about God according to truth, but in a mocking or blaming way. This sin is opposed, therefore, to reverence rather than to faith, and will be treated later among the sins against the virtue of religion (see Vol. II). Example: A person in anger at God says scornfully: "God is good!"
890. The nature of heretical blasphemy will better appear, if we compare it with other kinds of speech disrespectful to God.
(a) It differs from maledictions or curses, (e.g., "May God destroy you!"), because the one directly offended in blasphemy is God Himself, while in a curse it is some creature of God.
(b) It differs from non-heretical blasphemy, from perjury and disregard of vow, from vain use of the name of God, because none of these necessarily proceeds from a lack of faith, as does heretical blasphemy. Non-heretical blasphemy proceeds from hatred or contempt of God, perjury from presumption, disregard of vow from disobedience, vain use of the Divine Name from irreverence.897. Different kinds of blasphemy must be noted with reference to the duty of confession.
[a] There are three distinct species of blasphemy—non-heretical, which is opposed to the virtue of religion; heretical, which is opposed to religion and faith; diabolical, which is opposed to religion, faith and the precept to love God. These species should be distinguished in confession. Examples: Titus, angered because his Patron Saint did not obtain a favor for him, ironically turns the Saint's picture to the wall, saying: "You have great influence with God!" (non-heretical blasphemy). Balbus in similar circuмstances said: "I have lost all faith in Saints" (heretical blasphemy). Sempronia, Whose child has just died, rebels against God and calls Him a cruel monster (diabolical blasphemy).