I saw a bright white light before my mom died?

Before my mom past away. I was upstairs in her room watching tv, because the Hospice nurse said I should get some rest because after midnight she was leaving and I was going to watch her. I couldn't get any sleep, so I was watching tv for a few hours, going downstairs every once and a while checking on my mom. Out of the corner of my eye, I saw a bright, white flicker of light on the stairway wall. I look in that direction fully and I didn't see anything there. I thought the Hospice nurse turned on and off the light in the living room real quick, but the light in the living room that was reflecting on the stairway wall wasn't that bright white light. I sort of thought I was seeing things. A few minutes later, I went downstairs to go check on my mom and the Hospice nurse was standing over her saying my mom is starting to pass over. She died minutes after I saw that flicker of that white, bright light. I didn't correlate the white light I saw and my mom dying until after a few hours she died. Was it angels getting ready to take her to heaven or was it a sign from her letting her know she was about to die, so I could be with her when she left earth? I know no one will have the answer to this. I'm a sane, intelligent, reasonable person who doesn't look for supernatural signs like that. I'm not one to say, "Look guys, this potato chip look exactly like Jesus. It's a sign from God!" I would be interested to know what some of you people think of what the flicker of that bright, white light was.