Nowhere do we teach that forgiveness means tolerating sin of any kind, especially abuse.  Forgiveness does not mean staying in an abusive situation and giving the perpetrator more opportunities to inflict damage.  The loving thing to do is to confront abuse and help the perpetrators acknowledge and accept their responsibility.
At this point, you might find it helpful to understand that forgiveness and reconciliation are separate issues.  Forgiveness is necessary even when reconciliation may not be possible.  In many situations, emotional healing from bitterness, hatred and anger is necessary, but reconciliation is impossible or inadvisable.  A person who was abused by a now deceased parent, for instance, will never find healing by waiting for the offender to repent.  That person can't, and many other people won't.  The deceased abuser has already met his or her Maker and Judge, and hanging on to bitterness and hatred won't help you or impact that person.  Also, a person who was ritually abused needs to find emotional healing but should never be reconciled with the perpetrators.  Simply put, forgiving is releasing a debt.  It is agreeing to live with the consequences of another person's sin and relinquishing the right to seek revenge which God assures us is His domain (see Romans 12:17-21).
Some believers, however, have used Luke 17:3, 4 to teach that we should not forgive unless repentance occurs:
"Be on your guard! If your brother sins, rebuke him; and if he repents, forgive him.  And if he sins against you seven times a day, and returns to you seven times, saying, 'I repent,' forgive him."
This passage focuses on forgiveness in the context of reconciling a relationship in which we are called to rebuke sin and help bring others to repentance.  It doesn't specifically say that we shouldn't forgive if they don't repent (even though this may be implied).  Furthermore, we are not called to play the role of the Holy Spirit, rebuking every sin in every person we meet.  Honesty about sin is necessary for genuine reconciliation, and there is a time to refuse a cheap reconciliation without repentance. But note that Christ's main point here is not about withholding forgiveness but extending it, even repeatedly, to someone who is struggling in the relationship.  We are to be grace-givers, not repentance-demanders.
As we take people through the Steps to Freedom, we find that people who wait for another's repentance are locked in bitterness toward literally dozens of people.  Many are still bitter about an old boyfriend who jilted them or a boss who passed them over for a promotion.  We see little gained by hanging on to bitterness and somehow trying to exact repentance and force reconciliation.  Our freedom cannot be dependent upon whether another person will repent.
In the Steps, we deal primarily with the volitional and emotional side of forgiveness as it relates directly to our relationship with God.  Jesus says, "Whenever you stand praying, forgive, if you have anything against anyone; so that your Father also who is in heaven may forgive you your transgressions" (Mark 11:25).  Here, forgiveness is not portrayed as some long, drawn-out reconciliation process.  It can be done while you stand in prayer.  Nor is forgiveness shown to be conditional, extended only to some people for some transgressions.  Instead, forgiveness is pictured as part of our normal prayer life, it is extended to anyone for anything, and it may not be a prelude to reconciliation. Furthermore, forgiveness on a human level is necessary if we are to experience forgiveness from God (see Matthew 6:12,14,15).  Forgiveness is also a crucial element in resolving anger and bitterness (see Ephesians 4:27,32).  Only when we are free from bitterness can we pursue reconciliation from a biblical perspective and a godly attitude.