Inheritance dispute

[threesenoughthanks]

I'm going give as much of the story as I can but may alter a few details.
I am the eldest of four siblings. The other three all moved away many years ago and I have always cared for my parents. My mum died a couple of years ago so just my dad left. Two siblings have had no contact with our parents in over twenty years. One has a little contact (phone calls and visits once or twice a year)
My dad had a recent cancer diagnosis and now lives with me and my family. He has decided to change his will to leave his half of his property to me in his will (the other half taken up by my mum's care home fees)
Now the problem. There has always been a family rumour that my dad was not actually my dad. He totally denies this but to be honest I think it is true he isn't.
My sister isn't very pleasant. Could she contest the will on the basis that he isn't my real dad?
Thanks for reading all of that

Assuming you are in England or Wales, your siblings cannot contest his will on the basis that he is not your real father. They can contest on the basis that the will is invalid (e.g. that you improperly influenced him) or that it doesn't make reasonable provision for them (unlikely unless they are very poor). But whether he is your biological parent is completely irrelevant.

I am, like Collaborate (who is a solicitor), puzzled about the care home fees bit.

If you want to keep the peace with your siblings, you can execute a deed of variation after he dies. This allows you to alter the terms of his will. You could direct that it all goes to charity or you could share it with your siblings. I suspect, from the tone of your post, you don't want to do that but the option is available.

Just to hopefully clarify. My mum was in a care home for many years and amassed a bill of over £100K. As my dad was still living in their jointly owned home this has not been paid until my dad passes and then the house will have to be sold to pay her bill.

I think you should query the care home fees. I can’t find anything that says your df is liable for the fees as their home was joint. Everything I’ve read says if the home was jointly owned and one person goes into care, it can’t be used to pay for fees

Whether you are his biological daughter or not won't have any relevance, so that shouldn't be an issue.

There are other avenues to contesting a will that may be applicable though. Who is in the house now? If someone is living in the house they may be entitled to claim as a financial dependent.

We are going through a will dispute on our family. We were advised to give a nominal amount to the other siblings. Not sure if that was the best advice but that's they were told.

If you think it may be challenged I would suggest using a contentious probate solicitor to draft the will, they will have a better idea going forward.

My mum was in a care home and the fees were around £800 -£1000 a week for 4 years
As my dad lived in the home the local authority couldn’t and wouldn’t touch it . It’s the law
I would be checking out the legality of this first it’s not been unheard of for care homes and LA to be evasive with relatives