Just gonna jump in here ok?
Agent Romanoff had been lingering at the back of the SHIELD crowd, come to pay her respects, her life just seemed to be an endless line of missions interspersed with funerals. She'd been in the process of walking away from the SHIELD group, having some other things that needed taking care of and left the others to mourn. Over her long years she'd learned that sometimes the best way to carry your grief was just carry on. She's two yards away when it happens, the woman came tumbling out of the tree and the Agent reaches straight for her gun and pulls it out.
Natasha doesn't recognize this mystery woman and keeps her gun trained, she's familiar with almost everyone in affiliation with SHIELD, because it was her job to know and she did not know this woman. Upon closer inspection there was something a little familiar about her that she couldn't quite place. She'd never seen anyone like this before and wasn't really the trusting type when it came to masked strangers, unless she knew them. Approaching quietly behind with her gun, she notes that she's talking to that guy Hawkeye from the Avengers team. She reaches the tree, her gun pointed lazily at the back of the woman's head.
"In case you hadn't noticed, this was a private party and I don't think you were invited" She says, evenly looking at Hawkeye with a look that says 'who the hell is this? Do you know her?'.