Umineko no Naku Koro ni

[Buffalobiian]

Ange's interaction with Maria also shows that she is very affectionate to the people she loves, and judging from the information we have so far, Ange loves Battler the most.

I agree with this, but I also think she'd feel annoyed at how Battler's failing at something she may find easy, or where his approach to the problem is obviously incorrect to her. Looking at her love for Battler, I predict he would have been someone she relied on and looked up to when she was little. I wouldn't be surprised if that childhood admiration lead her to believe that Battler would be better than her despite being of similar age. The greater her expectations of him were, the greater the disappointment.

Not to say she doesn't love him anymore, but I don't see her attitude as being as much of a "strong front" as you suggest.