What does this mean on Facebook?

[netman.mcse]

A friend of mine used to get on Facebook via her cell phone all the time, so there was the time of her last activity next to a cell phone icon beside her name in sidebar.
But it's been almost 2 days, that there's just that cell phone icon next to her name without any number (latest activity).
I wanted to know what does this mean? I don't think she's online, because as i said it's almost 2 days that it's been like this.
Other mobile-friends in my list still have the time next to their names.
Thanks
I said "I DON'T THINK SHE'S ONLINE, BECAUSE AS I SAID IT'S ALMOST 2 DAYS THAT IT'S BEEN LIKE THIS.", she's been ONLINE for 2 days !!? isn't this wired !?