From what she's revealed about herself (My Dress-Up Darling is loosely based on her own experiences with cosplay) and what I was able to discern from her earlier manga (if the ecchi content in them is anything to go by, Marin Kitagawa's questionable taste in visual novels might have a basis in reality), she seems cool, but there is literally nothing about her on the internet, other than her name - a name that might be a pseudonym, for all we know - and what few manga she's authored.

Have Japanese sources shared more about her, or are we in the presence of the mangaka equivalent of Lordi or Ghost? It'd be funny if the author of a vaguely ecchi romantic comedy were to pop up at some award show in a full mecha suit cosplay, just saying. :P