First thing is to do it for YOU, not everyone else. Look around at anything that is not quite right and see what there is to fix. I guess that not working is quite a transition - it was for me. So are you planning to work again? Are opportunities/ travel better where you are? If not, then you need to look at what is available for you in the way of leisure etc.
Two hours is not a long drive to see Mum, but perhaps a regular short stay would help her get back into the swing of her pre-bereavement activities and pick up a few more. Being of that age, I have a number of widowed friends and it does take a variable length of time to get going as a singleton, but they are out and about trips and holidays, walks and craft and lunch clubs etc. We have a really active U3A , WI and Trefoil Guild that most of them are never home!
Things change quickly. If you can afford to keep moving you have many more options, but I am guessing that both the cost and the upheaval are a bit much.
Your daughter is being neutral, I guess, but she may appreciate your nearness if children appear, as would you.
And should YOU need support then it is better to be nearer her than your mother.
Your brother is a grown man, and you are not responsible for him, nor should you burden yourself with him, or you will find yourself looking after him in your retirement. (My disabled brother lives 200 miles away, but I provide online and advocacy support without having to clear up around him).
Is it practical for mum to move your way?