Basically, her point is that it's reasonable enough, given what Christians believe, for them to be concerned about the spiritual welfare of the non-Christian people they love and to want to share their beliefs with them. Nevertheless, there has to be a limit: if the non-Christian isn't interested and makes it plain that they don't want to talk about the issue any more, then the Christian ought to respect that and let well enough alone.
And I agree. There's a difference between sharing your faith and shoving it down someone's throat; a difference between talking about spiritual matters when the subject comes up and harping on it until the other person is ready to scream; a difference between discussing one's faith as part of a natural two-way conversation and callously ignoring everything the other person has to say so that you can deliver a prefab sermonette.
Unfortunately, a lot of well-meaning Christians make themselves odious by trying too hard to get their message across, and giving non-Christians the impression that they're being preached at solely to fill some kind of religious quota. "Delivered a four-point gospel sermon to X today, that makes three this week, go me!" It's no wonder that people react negatively to this kind of aggressive, impersonal approach -- but all too often, the Christian merely ends up consoling himself that he is "suffering persecution for Christ's sake", and then going on to treat the next person they meet in precisely the same pushy, insensitive way.
But when you look at the New Testament, however, we see a quite different model of evangelism. Christ and His disciples preached an uncompromising message, and they were not afraid to speak bluntly when the occasion demanded -- but they didn't chase people around thumping them with Scripture or making endless emotional/psychological appeals to "give your heart to Jesus today". If the people who heard their message genuinely wanted to know more, Christ and the apostles were glad to talk to them -- but if their audience proved indifferent or hostile, they let the matter be and moved on.
But it gets even more radical than that. Far from doggedly pursuing every person who showed even the slightest interest in spiritual matters, Christ often said difficult, offensive, or problematic things specifically to weed out the uncommitted and leave only genuine seekers behind. He made no attempt to woo His audience by playing down the difficulties and challenges involved in following Him, or selling them a "prosperity gospel" in which all their earthly problems would be solved and all their material needs satisfied if only they would believe. Instead, He warned that those who followed Him would suffer persecution, even death, for His sake; and He reminded His would-be followers that "foxes have holes and the birds of the air have nests, but the Son of Man has nowhere to lay His head." In other words, He was actually prepared to drive people away if they weren't serious about seeking the truth and willing to count the cost of true discipleship.
Convicting people's hearts and changing people's minds is not the Christian's job -- that's something that only God's Holy Spirit can do. If a person has hardened their heart to the gospel, either temporarily or permanently, then it is not the business of the Christian to hammer at that wall and try to bring it down. We are called to bear witness to the truth, to speak it clearly and courageously so that others can hear, but we are not called to cajole, manipulate, brainwash, or badger our audience into accepting the message, no matter how genuinely concerned we may be for their eternal welfare, no matter how eager we may be to share the message of hope that has made such a difference in our own lives.
Part of what it means for man to be made in the image of God is that we are not machines, to be programmed as anyone sees fit: we have free will and the capacity to make our own decisions, whether those decisions be right or wrong. If God Himself has granted us the power of volition and the freedom to use it even though the results often grieve Him (see, for instance, Ezekiel 33:11 and Luke 13:34), then Christians should also respect the choice of non-Christians to temporarily or permanently reject the message we preach. We can sorrow, we can pray, we can leave our doors open in hope of future opportunities, but we must not try to force the gospel into a person's heart, or we run the risk of hardening that heart still further against Christians, the Christian message, and indeed Christ Himself.
We also run the risk of being found guilty of pride, for how do we know that we are the ones God has chosen to bring that person to Himself? What makes us think that we are the only Christians that person will ever meet, or the only agency by which they will ever hear the message that Christ loved them and gave Himself for them? "'Bibles laid open, millions of surprises,'" said C.S. Lewis of his own slow and reluctant conversion, quoting George Herbert, "'fine nets and stratagems.' God is, if I may say it, very unscrupulous." Sharing the Good News with others is our calling and our privilege, but we are only one of many tools in the divine workshop. To insist that we and we alone should be responsible for leading a person from unbelief to faith is at best ignorance of God's greatness and mercy, at worst mere selfish conceit.
It takes God-given courage to obey Christ's command to "Go into all the world, and preach the gospel to every creature." But it also takes God-given wisdom and humility to know when to stop preaching, and indeed to recognize that there are times in people's lives when we do better not to preach to them at all.*
* I am not, by any means, claiming to always have been in possession of such wisdom, or even to possess it now. However I hope, by the grace of God, that I am learning.