I think a lot of things could change if she survived to ep 5, one of the more prominent of course being Kenny.
For one, i doubt he would have changed to being more selfless if Katjaa were still there, but you never know. Personally i think he still would have held onto that "my family comes before anything and anyone else" mentality all the way to the end, and this would possibly cause him to refuse to join Lee in the search of Clementine. Then again maybe Katjaa would convince him to go, but i don't know.
Maybe Kenny would refuse to jump in the hole to save Christa(since he still has family to protect) and she would die there. The same goes for Ben, though honestly....i think it would be Katjaa who fell and was impaled instead of Ben in that scenario. Not because of her weight, but because all it took was one more person. If she went before Ben, she might have fallen and Ben would be unable to jump across. Then Kenny dies trying to save Katjaa, and Ben is on his own.
Overall I'd be glad if she survived.
Heh, can you imagine if Lee went through the walker herd with Ben? The poor kid would probably die immediately.
"It's a natural instinct to fight for our own survival. What makes us human is that we fight for others." -AA:T&T