I blame Toph's non-existent parenting for the negative traits in Su's character, but yea, I can only assume the comics will attempt to fill in the stuff that wasn't covered due to budget cuts.
What I don't understand is why the new announced comic series, Avatar: The Last Airbender - Smoke and Shadow, is covering Aang's crew again.
The way in which the Bei-Fong mother-daughters dispute was handled in Book3 and 4 was less than ideal. The resolutions were simplistic and often painted the characters as simply
petty, rather than complex. In fact, in Book 3, when Lin was condescending about Su's new life and the size of her family, I assumed it was because of jealousy; that it was because she
didn't have a family of her own. Then I figured the most obvious reason she would show such contempt for her sister's family was perhaps because she couldn't have a family of her own; then
I immediately assumed she and Tenzen didn't get together was due to her inability to sire future Air benders. LOL that would have been great and made all her bitterness throughout the series
that much more relatable/sympathetic.
Missed opportunities EVERYWHERE in that arc.