This newcomer wasn't just anyone. He claimed to be Hades, Greek lord of the underworld himself. The potential for this to be far worse than Loki showing up was a very real possibility. Maria thought to get on top of this before any shit hit the fan. (Of course she didn't see any innuendo in that, thank you.) SHIELD training included building up a tolerance for a variety of substances so Maria could hit the bottle and be confident she could handle the situation.
She would have felt far more comfortable walking into this with a sidearm and her SHIELD uniform. Lacking both she was left with the confidence she could turn almost anything into a weapon, her hand to hand skills, a pair of well fitting jeans, plain tank top tucked in and a button down open tshirt over that. Flattering? That wasn't the point.
What she expected to find waiting for she wasn't sure, but what she saw was definitely nothing she would have envisioned. Maria couldn't help but pull up short to gawk at what she saw for a moment, blinked then continued on to the bar.