I'm bit surprised as My Mum and Nan Didn't have this as I Don't kno My Dad's Side of Family I presume it's From this Side ..
West Ireland Galway
Welcome to the forum, it can be a bit of a surprise to get a diagnosis as if in the prediabetes zone then people do not usually get any symptoms and it is picked up through routine health check or tests for other things. Many do not have any one else in the family with Type 2.
At least it has been picked up and you can do something about it, how much you need to do will depend on how far up into the range you are, 42-47mmol/mol is prediabetes so knowing where you are will guide you.
Many do find that making some modest changes to their diet is all that is needed, cutting out cakes, biscuits, fruit juice and sugary drinks and reducing portion size of other high carbohydrate foods like bread, potatoes, rice, pasta, pastry, breakfast cereals and tropical fruits particularly bananas, pineapple, mangoes.
Have a look at this link for some good explanation and some menu ideas for reducing carbs in your diet.
https://lowcarbfreshwell.com/