Also last year, my brother said that she was "losing her memory" because of certain things that she said to him. She also said something to my uncle that wasn't right. I just feel that the move was a little too much for her. She sold her house in 1 day and had 30 days to move out. My brother helped her with the move but there was no rhyme or reason to the packing. Thus I feel that a lot of her things that were in the computer room are in storage. I just don't feel that my brother really cares either way.
The only way to truly truly tell the yes or no of MCI is testing by a doctor. Stress can do weird things to your brain and memory. I have personal experience with this.
As a lay person's rule of thumb, normal aging is usually a slow down in speed but not a total blank. For example, you cannot remember someone's name when you want to use it in a sentence, but a couple of minutes later the name comes to you. With MCI's short term memory losses, you don't remember the name now or anytime in the next hour.
My mother scored 26 of 30 on the mini (27 is considered normal) and had a clear scans although they did show some small veins in the brain which have been associated with cognitive declines. The exam was prompted because Mom went to the bank to open a new checking account - forgetting she had already opened a new account at that branch just 2 weeks before. The neurologist said her brain was still thinking well but the memory problems meant the brain no longer had all the information needed.
Moving can make the memory problems seem much worse because everything is now in a new location and older established memories are not useful anymore. Your mother may be very stressed out when realizing she can't find anything. I suggest trying to organize things within cabinets and drawers the as close to the way they were in her home as possible. You might also consider adding some basic labels on cabinets/drawers (dishes, flour, towels, sweaters, tops, etc.) Because the contents of my kitchen cabinets was a close match to my mother's organization placing the "flour" label allowed my mother to turn to that cabinet for salt, spices, sugar, etc. that we both stored with the flour.
When my mother started panicking about every little thing, my brother thought our mom was just having a "pity party".
We moved her temporarily to an Independent Living apartment and the doctor and psychiatrist who saw her there insisted that we get her a neuropsych evaluation. This showed that she had developed MCI (it also turned out that the imaging they did as part of the evaluation showed that she'd had a stroke in the past, which we did not know).