In her book, Life in the Spirit: Reflections, Meditations and Prayers, she says:
We never try to convert those who receive [aid from Missionaries of Charity] to Christianity but in our work we bear witness to the love of Gods presence and if Catholics, Protestants, Buddhists, or agnostics become for this better men simply better we will be satisfied. It matters to the individual what church he belongs to. If that individual thinks and believes that this is the only way to God for her or him, this is the way God comes into their life his life. If he does not know any other way and if he has no doubt so that he does not need to search then this is his way to salvation. (Pages 81-82)
No concern for their eternity
You must have overlooked or not understood that part. You don't have to get into ones ear to teach the Gospels, its more effective if you simply get into their hearts. Its more genuine and appreciated.