Thanks for your enquiry. I am afraid that unless your Mother's Will specifically states that your Wife should inherit the Estate were you to die before your Mother, the Estate will pass equally between your 2 children. Likewise, unless your Mother is of sound mind now and is willing to change her Will to reflect this change, there is no way that your Wife can claim anything from your Mother's Estate. The only option open to her would be that if your children were to inherit, they can agree to vary the terms of the Will (called a "Deed of Variation"). This Deed in effect re-writes the Will post death and can be done anytime within 2 years of death. So, if your children agree, they could sign a suitable Deed of Variation, granting your Wife a proportion of the Estate.
I hope this helps and sets out the legal position.
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