It may be possible. You need to speak to an attorney experienced in wills and trusts. I will add that as a practice area for this question.
Consult with an experienced local elder law attorney about whether a special needs trust would accomplish your goals. You can find an elder law attorney here on Avvo by using the "find a lawyer" tab. It is not clear to me whether this inheritance will be coming from someone who has already died or not, but the options will be dependent on that fact. In any event, consult with an elder law attorney because even if a trust will not work, you ought to be able to get good advice on how to minimize if not eliminate the interference with her medical assistance, etc.
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Speakmto an elder care attorney who will have knowledge of Medicaid and other govt. supplements. A supplemental needs trust may be established to hold her share of the funds from the inheritance so as to not disqualify her from her current benefits. Understand that whatever money gets set aside may one day go to the govt.
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It depends on many things -- age, etc. The local attorney we use for such issues is Sean Bleck. I'll attach a link to his website for you. Good luck.
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