CM, you must realize that not everyone is on their guard every second. Those comments may be slightly careless, but heretical? Ease up on the throttle a bit.
True, it doesn't sound right to say that our faults make Jesus love us more. Having these faults and then overcoming them through His grace is what would impress Him. But how do you know that's not what she meant?
For instance, Peter's denial of Christ is more than a fault, but Christ knew he would deny Him and loved him anyway, because He knew Peter would prove himself later.
What she said also fits with her whole philosophy of greater and lesser saints. It could be a fault of St. Therese that she wasn't as powerful as St. Augustine, that she can't perform polemically like he can, that she can't fight heresies like he can. Yes, it says "commit" a fault, but this sounds more careless to me than heretical, because I don't think she's using the term "fault" theologically, the way a Pope would.
Probably the most disturbing thing that Ibranyi said about St. Therese was that she prayed for an unrepentant murderer, knowing he was unrepentant, and said God would save him anyway in His great mercy. That is disturbing, and could be even seen as witch-like, as sympathy for the devil. But it could also be seen as simply a passionate exaggeration of God's mercy at the expense of His justice, a naive blunder.
Remember, the Church is the spotless bride of Christ. It could not make these mistakes, or careless slips. But St. Therese is not the Church, nor are any of us except the Pope when he teaches from the Solemn Magisterium. If any of this is heretical, and we don't know if she corrected herself later, then I am ten thousand times the heretic that she was. I can't remember the last day I got through without messing up somehow.
Even St. Catherine of Siena, my favorite female saint, talked of her sins, and she admitted that for most of her life she fought with pride. There is a story about how she held a dying criminal in her arms and as he expired he said "Oh Catherine! Oh Jesus!" and she was very pleased about this. There is some pride there, that she takes pleasure in being mentioned as a savior figure along with Jesus. So what? She's human. She co-redemptrixed a bit, since she brought the dying man to the Redeemer. To Jesus through Catherine.