Hello and thanks for using Just Answer.
My name is ***** ***** am happy to assist you with your enquiry.
Provided your Father was of sound mind when he made his Will (which it appears he was), then a party can not contest a Will.
A party can make a claim against an Estate IF they were financially dependent on the deceased or the deceased had in some fashion promised the party a share in his Estate and that party had, upon reliance of that promise, done something to his detriment (eg given up their own home and gone to look after the deceased).
Neither of these scenarios appear to be relevant here, and therefore, from what you have told me, none of your siblings would have a chance of making a claim against your Father's Estate.
I hope this helps and sets out the legal position.
Hi Sam,Can I assist you any further?Kind RegardsAl
Hi Sam,Can I be of any more assistance to you?Kind RegardsAl