So my little sister is about to have a baby and we're all very excited! She's working really hard on her mental health and we're geared to deal with whatever her brain throws at her. 

Here is what I need advice with: I am my sisters Favourite Person™. I basically raised her and every other adult treated her like crap so my fumbling attempts at doing a good job have somewhat cemented my place, to her, as best person and parent. This is not really true, but that's okay. I try and remind her that I did the bare minimum and she deserves that from everyone. 

Anyway- I have two questions:  
1) How do I avoid my sister feeling like I love her baby more than I love her?   
This is something she's already expressed concern about. I know that being continually verbal about how much I love her etc will help, but since I'm going to be around a lot- probably living together- I will be taking care of bub a lot, especially to give sister a break when she needs it. I'm worried that that extra care and attention that babies need will translate to her as more love.  
2) How do I help her stop comparing herself as a parent to how she sees me as a parent?   
As I said, she sees me as being an almost perfect parent. I am not, but her perception is that, and that's not a fair standard for her to hold herself to. It is compounded by the fact that she sees me as more of a mother than our actual mother- so she is afraid her daughter will too. Our mother was horrifically abusive, and I cannot imagine the same situation happening. But she's afraid of that, and I don't know how to assuage her fears, because words alone don't seem to be helping. 