MacCarver has a stern face, and high cheekbones. She has short black hair seen under her helmet when you are near her. In the Venblesk City Street, she has her goggles over her eyes instead of on her helmet as normal and what appears to be a balaclava. It is unknown if this is or isn't MacCarver, but you can hear her voice on the radio, so it is likely.
Like Solomon, she uses the G36C. She also appears to be the better shot, as if you hide and spectate a battle, she will seem to get more headshots. In Naszran Foundry, she isn't seen, but she uses a Walther 2000, which she uses to provide you with sniper support.
If the player is idle, and watches MacCarver, she will screw a suppressor onto her G36C, yet it seems to have no affect.