Sorry about this being a link-to-a-link but Are Family Caregivers Invisible? is a great article link on being a caregiver in the workforce.
Having been a caregiver to three people at one time at the same time, I had to choose to be an unpaid, unsupported caregiver instead of working (Just in remembering that time I feel like crying). I have even left many a job over time because of those duties, the stress making me ill and lack of understanding from my employers. Now, in trying to get back into the workforce again, I'm worried that no one will hire me because of my caregiving duties for my husband and my friend and my employment history.
I'm a firm believer that corporate culture and the government needs to change to make it easier to be a caregiver particularly if you are precariously employed by not having enough hours to qualify for EI benefits, having contract work, self-employed , or are unemployed or on welfare/disability.