Ryan, checking the day hike permits, there are 54 available on Saturday, meaning 46 slots are reserved. So there should be a good number of people heading up the trail, so she won't be alone.
And the weather from NOAA (for elevation 13107) shows clear and sunny, predicting a high Saturday of 36.
She'll probably meet others hiking the same speed and be able to succeed. Whitney is not particularly tricky for the ice axe and crampons, so with her experience, she should be good to go.
If you head over Friday, she should call the Visitor Center and ask for a night-drop-box pickup of the permit, so she can get an early start. (760) 876-6222
...and I want a trip report! I may be heading over next week.
