You'll have to excuse me for not bringing my source, except I saw it in the Schottenstein Chumash, and my mind seems to remember it was Ibn Ezra or Ramban (perhaps someone can help if they know, otherwise I can try and look it up later) but...
It is said that Leah got annoyed at Rachel for asking for some dudaim, because she felt that Rachel was being self-centred (or something similar). It went further on to say that Leah was annoyed that Rachel married Yaakov after Leah, creating this competitiveness in the marriage in the first place (see Sforno).
I was really taken aback by this. How can we reconcile this with the fact that Leah was a Tzaddeket? Leah knew that Rachel was supposed to marry Yaakov and he was tricked into marrying Leah instead. Despite that Rachel didn't want Leah to be embarrassed so gave her the passwords etc during the marriage.
So, it seems to me that in the name of normal human decency, Leah should a) feel bad that due to their father's evil, Leah married Yaakov when that wasn't his or Rachels initial intention - basic bashfulness is a trait specific to the Jewish people... and b) feel grateful that despite that, Rachel looked after her and made it as pleasant as possible.
Instead, she now is annoyed at Rachel, has no empathy that Rachel has no children, and in fact thinks that Rachel did something wrong by proceeding as planned and marrying her love, Yaakov? It just doesn't add up to me.
I get that Leah was also a victim in all this, and had her own problems of feeling unloved, but should that really be a cause for this indecent reaction?
Help me understand.