angel likes to volunteer for animal shelters, the elderly, at children's hospitals, etc. so if she does any of that maybe they've seen each other at a few places? another idea i have is she works at the driskill hotel as a part-time masseuse. maybe she saw her at the bar during some down time and some old guy was trying to hit on her. angel would've swooped in and put an arm around her like "hi honey, sorry i'm late," and played doting gf until he left.