What matters is this: whoever she was, Aunt Esther Gubbins was right. (Para. 19)
Meaning: What is important is that no matter who she was, Aunt Esther Gubbins was right.
matter: vi. be important
In a composition, teachers are concerned that students express themselves correctly, but what also matters is that the thoughts are complete and well sequenced. 在批改作文時(shí)，老師會(huì)注意學(xué)生表達(dá)是否正確，可同樣重要的還有表達(dá)的思想是否完整以及組織是否合理。
The cost of heating a home does not matter to someone with a lot of money, but for families with low incomes, it is a matter of great importance. 對(duì)于有錢人來說，家庭取暖的費(fèi)用算不了什么，但對(duì)于低收入的家庭來說，卻是一件大事。
whoever: 1) no matter who
Whoever broke the window, he should pay for the damage. 無論誰(shuí)打破了窗戶，都得賠償。
2) any person that; who
Whoever wants to go may sign their names on the paper. 凡是想去的都可在這紙上簽名。