Moving in with daughter and son in law

Hello all, we're new here so apologies if this is not in the correct forum. My wife and I are both 75 and bar the odd ache here and there and some stent surgery around 10 years back we are in great health. Our 3 bed semi and garden are just beginning to get a little large for us to comfortably maintain. Over the last few months of lockdown my daughter has done all of our shopping and errands and has been a godsend. Around 3 years ago my son-in-law said he proposed to have his double garage converted into a "granny flat" with a view for parents to move in when needed. The builders did a great job. Though the Granny Flat is attached to my daughter and son in laws main house it has its own front door, a small living area (though I suspect this is larger than many living rooms in new 2020 builds!), a large ensuite with walk in shower and a bedroom. We have recently talked about downsizing and then my son-in-law said we could move in with my daughter and him. This is something we are considering. We have always got on so well as a family (ie spending most weekends with each other and the grandchildren and regularly going away for a week or two weeks holiday with them. My son also joins us each and gets on so well with Son in Law and his sister) so moving in with them doesnt cause anyone any worry or concern. Yes that the the "Granny Flat" will give us a smaller home buts that will make it easier to manage with our own private garden (maintained by son in law thankfully) it will still allow us our independence and privacy (and most importantly still gives my daughters family privacy also). We will spend more time together when we want to etc and they have said they will be happier if we are living with them as we "age" - that depressing word!!! My daughter and son-in-law do not want us to pay any rent etc but we will give towards electric/gas costs and food of course. We have a good pension and savings etc and the house has been free of mortgage for years. Anyway my husband and I are looking to sell our home and I would like to give half of the proceeds of the sale to my Daughter and Son-In-Law and the other half to my son. We've always told the children that the house is their inheritance anyway as we plan to enjoy and spend our pension and savings whilst we can enjoy them! Would the pose any tax implications for them or even though we are in good health now could it be looked upon as dispersal of funds etc if down the line we need to move into care. To be honest my children could make more use of the money now and we will be happy knowing that we have helped our kids long before we depart. Anyway your thoughts on this would be appreciated.