My mom is 84 and had a valve replacement surgery 4 years ago. She is on multiple medicines (including a blood thinner). A side effect listed on a couple of her medicine bottle labels is drowsiness. She generally, sleeps 8-10 hours each night and often may nap another couple of hours during the day. She usually drinks a cup of coffee in the morning. Should I be concerned about this amount of sleep? Should I encourage her to have a second cup of coffee later in the day? Thanks.