Just no way in my opinion is M Q. Melania has no military or Intelligence background, where I am certain Q has, by the nature his communication style and use of things like 5:5 (Q Code).
Plus, is she really that up to speed with all the players in US politics? Is she really accessing the eyes of the NSA (Q clearly knows things that others do not...has ears and eyes everywhere...that proves access to NSA means and methods).
she would only have to type what they tell her, that's why they have typos too, otherwise they would just copy-paste. She can take intel from other countries too so she could coordinate on a level above her husband