My dyslexia was diagnosed fairly early on due mainly to my dyscalculia, as my dyslexia is barely noticable. The primary problems I have with words are where a couple of letters are repeated - banana, remember etc (I once spent half an hour on a third-year Poetry paper trying to figure out how to spell ‘odyssey’), and I can’t spell aloud to save my life. In my (extremely limited) knowledge/experience, mostly garnered from talking to other dyslexics, it has usually only been those with slight, rather than severe, dyslexia who have the accompanying problems with numbers.
I transpose numbers all the time, write my '2’s and '5’s back to front if not paying attention, and cannot keep any given number in my head for any length of time, which turn the cash management parts of my job into long, highly-involved processes involving lots of hastily scribbed notes and cursing at the spreadsheet. At the grand old age of 29, I still only know my 1,2 and 10x tables, and have difficulty remembering my own phone number, let alone anyone else’s. The current 8-hour (ick) time difference between myself and my SO is the worst headache when trying to figure out when I need to set my alarm or when it’s socially acceptable to call. I’ve figured out to carry a small calculator and notebook (for jotting down numbers) at all times, so as long as your collegue is aware enough of the problem to be able to usually counteract its effects, as it sounds like she has, I doubt it will become more of a problem for her, as it is no more than an mihor annoyance for me most of the time. In fact, I think it bugs the people around me more than myself!
(Another ‘thank you’ to kellibelli for the link, as it gives me a big fat excuse for my habitual lateness and appalling organisational skills:D)