Honestly, I'm not sure. Maybe somewhere between 5-15 years? It is horrible that Weaver (and maybe Richardson) murdered an innocent and defenseless baby, but I guess there is a part of me that also understands the fear, lack of support, and disassociation that these young women were experiencing. Not that this makes their actions in any way acceptable, and certainly a significant punishment is warranted. But I guess life imprisonment without the possibility of parole just seems excessive to me.
It is a significant punishment, for sure. I'm not sure why someone who kills in cold blood would deserve a lighter sentence. For example, I don't think this is any different than Chris Watts who killed both his little girls by smothering them. I think he deserves every moment he got in prison.
ETA: I also thought Casey Anthony deserved life in prison, no parole, for killing Caylee. I guess I don't see the difference because it happened right after birth and she was scared.