How important is it for a group home to offer activities designed to engage dementia patients?

I am getting ready to place my mom who has dementia in a lovely and loving group home along with 4 other residents. She will have her own private bedroom and bath and good care, but I am concerned that aside from exercise every morning and a "sing-along" with a piano player on Saturdays, there doesn't seem to be much else offered in terms of stimulation. My mom has been living with me and my husband and she likes to go everywhere with me--to the park, shopping, out to lunch, etc. She is 92 and still mobile around the house, but I do use a transport chair for her if there is much walking involved. She likes to go places, but she is also very content to watch T.V. She is very cooperative and just goes with the flow (yes, I know how lucky I am!). I will be able to spend time with her several days a week, but I am concerned that while I am not with her, her days will be spent mostly watching T.V. I don't think that would bother my mom, but I feel guilty. I would like to hear from anyone who has parents in a similar situation and also in big memory care centers where there seem to be a large variety of activities to in which to participate.