Communication from MC facility. Do these places have to provide any kind of reporting to family?

Does your MIL ask for her sherry? Is this sherry for some medical reason? Most facilities because of Covid are both under staffed and overworked. Most do not routinely provide written reports. Some provide a report at her planning care managemeeting. Contact the Administer or Director of Nursing. If you visit regularly ask a staff member.

They are going to have internal reports on things like doling out medications, how much she eats and how well her bowels are functioning, I'm doubtful that they keep track of how much or how often she has her sherry unless it is included on her medical chart. As for communicating any of this to family - in my experience that's like pulling hen's teeth, if you corner someone they may go through charts to answer a specific question but on the whole the philosophy is that family are not part of the care team.

Can you communicate with the person in charge of the kitchen, or the aids that are usually serving the food?
If so they would be the ones that you can ask to provide it.
Or ask that her portion be given at night when she is ready for bed (if it not contraindicated with medications she may be taking.
But with all that is done in a facility I would not make a big deal of this one thing.
If it is part of a list of items that she is supposed to get and is not getting that is different.
With dementia she probably is not going to "ask" for her sherry and she may not even remember that she is "supposed" to get it or that she even likes it.
With many things we need to pick our battles and fight and stand up for what is really important, health and safety is foremost. If everything else is wonderful consider yourself and MIL very lucky. thank the staff for the wonderful job they are doing and leave it at that.

I am not sure why these concerns, in all truth. You report your mother as content and happy in her new home, something that so few of us CAN say of our elders. You also describe the place as having wonderful staff, and being clean and accommodating. Given that, I am curious why you are so concerned regarding the sherry. If Mom cannot even remember if she had it or she did not, why are you asking her about it? The fact that she looks so good is indicative that she is eating well. Just my humble opinion, here, but given you were so wonderfully diligent in getting this marvelous placement, might it now be a time to relax just a bit regarding her daily intake? Were she living alone I don't think you would ask her, "So, Mom, are you sure you remembered to take your sherry today?" It really, while it may be much enjoyed, not especially medicinal.
Can you tell us why the sherry is such a concern to you, or reports on eating when your loved one is in a facility you judge to be pretty much four star, with you loved one looking happy and well fed?

I am with Alva here. If MIL cannot remember if she had it or not, doesn't seem that sherry is that important.

I may ask how the doctor wrote the order. If it says "give at bedtime" then it should be given to her at bedtime. If it says "upon request" then it will be given when she asks for it. It really goes by how his order is written. Aides, nurses go by the order. Plus, you can determine if she is getting it every day on how long it takes for them to ask you to bring in more.

My thinking is that nightly Sherry was one of the rituals your MIL fully enjoyed and you want her to continue having that enjoyment. If your allowed visits, I may ask one of the desk nurses "Is Mom enjoying her Sherry?" They can look at her chart and see when she got it. I would not make a big thing out of it because for one moment she enjoys it and then forgets.

I was lucky to have a daughter, RN, who worked in rehabs/NHs for 20 yrs. I would ask her what I should complain about. You need to understand that MIL will never be cared for like you would have cared for her. I am a little OCD. My Moms hair is what bothered me the most. It was kept short but very fly away. I provided a special brush to help with that. The aides never used it. They kept using those little plastic brushes that just put static in her hair. I put a note "Please use brush provided". It was right there on her night stand. So I carried a small brush and a small hairspray in my purse and did her hair while I was there. I also put her outfits together on one hanger, bra too because it got forgotten at times. (Mom broke out if not wearing a bra) My daughter explained to me the morning routine and night routines. Aides do most of the hands on with residents. Nurses usually are the paperwork and things aides are not allowed by law to do. One man on the forum complained they never put wifes jewelry on her. I explained that his wife was not the only person the aide takes care of. I know what it took to get one person up and dressed. What if you had 10 of them and it had to be done by the time breakfast is served. The last thing on their mind is making sure a resident is wearing her jewelry that day. And now, Medicare requires that PT/OT be started at 8am for residents receiving it. That means the aides are even on a tighter schedule.

You are your MILs advocate. There maybe things you should question but then there are things you may just need to let go.