I would have to know more and the question is somewhat vague but probably not, unless she is claiming you unduly influenced her mother. She could attempt to make a claim against her mother's estate if she thought that was the case. You should review your circumstances with an estate planning or probate attorney familiar with contested wills and estates.
Perhaps your question is whether your mother-in-law could prevail on a such a claim? If that is the case, it depends largely on whether you or your husband unduly influenced your husband's grandmother to change her Will to favor one or both of you.
"Undue influence" occurs when a party interferes with an individual's free will, preventing that individual from exercising his or her own judgment and choice. The following circumstances would raise a suspicion of undue influence: (1) active participation by you or your husband in preparing or procuring your grandmother-in-law's Will; (2) you or your husband's receipt of an unusually or unnaturally large part of your grandmother-in-law's estate; (3) a weakened condition of health and mental vigor of your grandmother-in-law; and (4) an opportunity for you and/or your husband to exert undue influence. The presence of these elements will not automatically invalidate a Will, but the combination of them may so suspicious as to raise a presumption of undue influence.
If these elements are present, you should consult with an estate planning attorney who can advise you on the steps you can take to minimize the risk that your grandmother-in-law's true wishes are overturned.
