Brother is acting alone in "caring for" elderly mother

England here.

Waiting to see solicitor - appointment made for 18th Jan, advice required before this.

Backstory:

I live in the same town as my Mum and most of our family. My brother lives about 90 minutes away and has a job where he can't just drop everything. We both have keys and know the alarm codes.

When Dad died back in 2012, mum summonned myself and my (younger) brother and told us what was in the will, where the will was (it was lodged with a solicitor) and that we were both executors. She also applied for Lasting Power of Attorney for Finance and housing - because she had issues in the past with family members whose mental health was failing and she didn't want us to go through this.

Mum started to get forgetful from 2017 onwards, small things at first such as putting her keys somewhere safe (in a cereal box) to forgetting to lock the door and set the alarm. She also started to have falls and had a heart condition that started two years before.

In Late 2018, she started to forget major things, such as who I was, and who my children were - confusing me and my brother's families. She also had a forgetful episode when we travelled to her sister's for the funeral of my Uncle in early 2019, sat waiting for a coach in London and then the next minute she questioned where we were and why we were there.

In June 2019, she forgot where I lived when attempting to deliver birthday presents.

We attended a wedding in September 2019 where she either forgot to bring a card for the bride and groom, or put the card down somewhere and lost it - no-one knows and the bride and groom confirm that they didn't receive a card. I managed to convice my sister-in-law that mum's health was an issue but I couldn't do anything about it as the doctor wouldn't speak to me. She convinced my brother, and They suggested to mum that she apply for Lasting Power of Attorney for Health.

Covid hit in 2020, and Mum moved her mother in to her house with her. We bought some groceries, and continued our phone calls. I went round and did the grass cutting and the DIY jobs outside, always staying safe.

Start of the trouble.

December 2020, Mum went to stay with my brother for christmas. She called me to say that she was doing that, and could I keep an eye on the house for her please. I agreed. When I went round, the locks had been changed.

I tried several times to call her into the summer months, but each time I went round, no-one was in and each time I called her phone or mobile, it just rang.

Several things happened very quickly at this point. I received letters in October 2021 stating that both Lasting Power of Attorney applications had now been revoked - something that primarily mum would disagree with and secondly that she didn't have the mental health to be able to do that - I believe that my brother and sister-in-law did this deliberately.

Within a week, I stumbled upon an estate agents video of her house being put up for sale - it was sold quickly - and then she simply vanished. It was only through managing to spot a family member's car and following it, that I tracked down where she was living - another family member confirmed that.

I've now found that my brother had her over to his house during the heatwave in summer, but for some respite, he put her in a care home where she has been ever since.

I am going to go through all this with a solicitor, but before I do I would like to know the following:

1. Mum would never cut me out of the loop unless my brother lied to her or directly acted on her behalf. Would there be any criminal action here, or would it remain a civil matter.
2. If they've revoked LPA, the chances are that they've also got her to change her will and stopped me being an executor. Again, mum wasn't really of sound mind and so it wouldn't be her requesting this. I can't see the will or enquire about it until she's dead, so what do I do to check this in the interim.
3. If my brother has done all of this, would it also constitute Elder abuse, Coercive control, Fraud?

I just feel so defeated at the moment and could do with some answers to set my mind at ease.