Fishy??

Father was adamant that his estate should be split 50/50 with myself and my sibling as stated in a will created 7 years ago.

Fully capable though she refuses to work and has lived rent free with him for 5 years up until his death last week. She ran a few errands and gave him a few rides but in reality, he took care of her. And she manages to find plenty of others to pay her way, including you and I via public assistance.

Four months before his death, he started paying her $400/month. I found out after his death when reconciling his check book last week. Asked her why and she mumbled something about to have money for bills. She did not cash the last check and "tore it up because she didn't feel right about it".

He also opened up a joint bank account with her and pulled 11,000 from his/my joint account so she could "pay bills" but I was to be the executor and the bulk is in my account. Why does she need an account?

2 months before death, will was changed from 50/50 to 90/10 her favor. She claims "no idea" why.

Sister said dad was forgetting things and may have had beginnings of dementia

Was told her son-in-law (a lawyer) will be buying the house (I was not asked if that was ok). He has been talking about it for years.

Thoughts of any undue influence?