If you correctly indicated what the will states, your reading of it appears to be the right one: the 5 grandchildren would split 1/4, or each get 1/20th, while the three "girls" each get 1/4. That is the logical, reasonable, and hence enforceable reading of what you describe.The trustee is right in one regard: if you disagree with her reading of the will, you need to bring a legal action in country court seeking a "declaratory" judgment, or court determination, of how the will should be read and enforced, and a court order that the trustee distribute the assets the way court found. And if you are going to do that, you want a lawyer: this kind of a lawsuit is much more complex procedurally than, say, a small claims case, and based on what you write, if 1/8th annual is $15,000, then 1/4 annually would be $30,000--that is, there is $15,000 PER YEAR at stake based on how the court interprets this, and for that much money, it is well worthwhile to hire a lawyer to help you.