"By the way, as stated, she has an irregular period. Does this, in any way, come in the way of the Morning Pill's effects?"

If you mean that she had an irregular cycle before taking EC (the morning after pill), then no, it won't impair the effectiveness of the medication. All it might mean is that -- since she ovulates irregularly -- it would have been more difficult to predict when she had ovulated or was going to ovulate this cycle. Because of this unpredictability, it might actually mean it was a bit better to take EC than not to take it since you weren't sure of whether she was fertile at that time or not, kind of like a "better safe than sorry" thing.