What effect did Renesmee's bite have on Bella when Edward placed the baby on her chest.
I understood Renesmee to be non-venomous, so I assumed that Bella was dying from the trauma of giving birth not from Renesmee's bite. Is this correct?
This is correct. However, at the time Bella was not aware of this. Only later when asked by the Volturi did Bella realize that Renesmee was not venomous. Bella was dying from giving birth to Renesmee because her body could not take the trauma of the baby being ripped from her body. This is why Edward stood by ready to inject Bella's heart with his own venom and why immediately bit her in as many places as he could, to keep her from dying.
Because Bella's daughter did not have any venom, it would not have hurt Bella. However, Bella was dying from the strain of her baby pushing itself out of her body. She could not take that and would have died if Edward did not save her.
Yes, Renesmee's bite was harmless however under the circumstances of birth Bella was dying from the trauma of birth since the placenta had disconnected and the baby was basically every which way in order to get out so Edward had to ripe Bella open to get the baby which resulted in huge amount of blood loss. Also Bella was in a coma for the most part except for that one moment where she gets to meet Renesmee. Another part of the reason she was in and out would have to be the morphine the gave her.
yes. you are. Bella was losing an extreme amount of blood and her body was already so fragile and weak. Other then pain Renesmee bite did not do anything to Bella.