What a dilemma. Mother is sleeping peacefully and you are getting simultaneous and much-needed respite. You referred to her medication regimen and I am wondering if a med or combo
of meds could be the reason she is so sleepy during the day. Checking with your pharmacist about her drugs would be an easy approach and may provide a possible solution.
Another looming question is how she sleeps at night. If she is sleeping all day and awake at night, neither of you is establishing an appropriate sleep pattern. If this is the case, then you definitely need to engage her in more activities during the day; walking, doing chores together, and being outside as much as possible help to provide a better night's sleep.
Since your mom eats very little, I would suggest the following:
* Be sure to provide as much healthy nutrition during her dining times.
* Keep nutritional snacks handy and in plain sight - fruit slices or grapes and nuts (if she can chew)are good choices.
* You can purchase dietary supplements such as "Ensure" or make your own combination drinks in a blender. Some recommendations would be to whip together a fruit yogurt with a banana and a 1/2 teaspoon of wheat germ...Yum!
* This is worth repeating - get her out doors as much as possible to stimulate her appetite.
If your mom's medications are life-threatening if withheld, then obviously you must awaken her to take them. Again, make your pharmacist your 'new best friend'.
There appears to be a point in the progress of Alzheimer's when appetite does greatly diminish and weight loss becomes quite noticeable. It is more important to give mom small nutritional drinks and snacks then to be overly concerned about the amount of food she eats.
Do talk to your PCP about her sleep habits to rule out any underlying medical conditions. If she is A-ok medically, then keeping her engaged as much as possible, during the day, is the most likely solution.
Do take care of you!