She became so important to them that they wondered how they had ever managed without her in the past. And the longer she stayed with them the more indispensable she became, so indispensable in fact that their one fear was that she might some day move on.
English is necessary as at present original works of science are in English. I believe that in two decades times original works of science will start coming out in our languages. Then we can move over like the Japanese.