My take on this is that if it was for personal injury, then you sued on behalf of your mother and/or her estate. Therefore, the award would go to the estate and your mother would have assets to pay back the Medicaid. If this was a wrongful death suit it would be a different story, but I do not think this is what happened. One way to look at it is who would have received the money if she had not died. Sounds like your mother would have.
Any individual seeking legal advice for their own situation should retain their own legal counsel as this response provides information that is general in nature and not specific to any person's unique situation. Circular 230 Disclaimer - Advice given in this response cannot be used to eliminate penalties with the IRS or any other governmental agency.
You should have a probate attorney look at the paperwork to help you reach a determination.
It would depend on the type of lawsuit. If you brought this suit as the executor of your mother's suit then the money would be paid to her estate and the state would have a right to estate recorvery. If the suit was a wrongful death suit then the answer might be different.
Most tort attorneys would not be familiar with Medicaid so I would give your attorney credit for not knowing. I would think that it would depend on how the funds are being received. If the nursing home is writing a check to the estate then they are definately subject to recovery as it was your mother's money. If you or your sibling received some type of compensation out of the claim then it would not. I would have a probate attorney review the check with you and potentially negotiate with Medicaid if it is made out to your mother.