I have never been in a child care enviornment (daycare, preschool, school, church, etc) that the only thing a child could do was watch TV... or there was only one choice of things to do at all unless it was a structured activity or learning time. For example at my daughters preschool they have play time before school begins while all kids are being dropped off and teachers getting ready, etc- there are tons of activies to choose from, color, draw, cut paper, play dolls or kitchen, sand box (which is really cool that there is an inside sandbox) blocks and legos, cars, etc. Same at church (puzzles, coloring, books, even some free run and play time, etc.) Even when TV is an option (which isn't often) they don't usually force them to watch if they can do something else not interferring with those who are watching (unless the tv program goes along with the lesson - like veggie tales as church or something).
Maybe she is running around and causing disruptions or something and that is what she is getting in trouble for. I would talk more detailed (if you haven't already) about exactly what she is doing that she is getting in trouble for. If it is that she is required to ONLY watch TV at this time- you should maybe consider another daycare (if TV time is not in your beliefs). I can understand that they want the kids to have some down time before going home- but she should have options of other quite activities as well.
**After reading some of the other posts I wanted to add something- if they are making the kids sit down to watch tv because everything has already been cleaned up and they don't want a mess again then shame on them! I have been a nursery, preschool and elementary volunteer at church for years... yes we try to clean up some before parents come to get there children but our jobs (which we are not paid for) is not over until after all children have left then we clean up, sanitize, etc. but we don't make the kids just sit in their chairs staring at the wall (or TV) until time to go. If they get a book out to look it- we ask they put it back when their parents arrive. No big deal. Also most children who are old enough to sit and watch TV are also old enough to put toys, books and puzzles back on the shelves where they got them. I spent a morning at my daughters preschool and was amazed 30 kids playing with 100 toys it seemed. Teacher said "Time to clean up" and everything was back in its place within 5 minutes without an adult lifting one finger! Wish it were that easy at home. LOL
Hope this helps :)