I wish I had a solution for you, but I haven't had this problem. But then again, I don't think she's ended the week by working the last day. She keeps ... um ... getting pregnant before the week's over (lol). If I come across the problem and find a solution, I'll certainly share!
The problem I have had instead is my sim getting stuck carrying a toddler. I have to watch the time closely so that she's not holding anyone when it's time for the daycare to close. If she is, she gets suck holding the kid, even though the parent shows up to get him/her. My sim will appear to be going somewhere, running out to the road as if leaving, but her status bar shows only that she's holding the kid. She gets the path blocked bubble but continues to stand at the road, holding the kid, trying to do something. I can reset her and she's fine until the next time she's holding a kid at quitting time. I don't know about career gain though for that kid. I'll have to pay attention the next time I slip and let it happen.