Being a "good mom"

One of the things that's been difficult for me is the duality between what I've always felt was right and just making my kids happy, and the way this is hard to balance because I just want to lay myself down for Liam in gratitude.
It may sound strange to say Liam, since I have two living children. But there is this strange element to my relationship with Liam since he was the first baby after Charlotte died. I was still so completely ensconced with grief for the first year or so of his life, that his being is really wrapped up in that. By the time Aoife came around, and was swept up into my waiting arms after a quick and easy birth, joy was my state of being. She is also at a relatively un-challenging age--20 months-- so there really aren't many power struggles.
But not so much for my three year old beauty. Now I used to teach kindergarten, and I think I was pretty good at it. The kids in my class were happy, jolly, creative, and they did whatever I said. I could see that setting firm, consistent, sensible boundaries with clear incentives and consequences really made kids understand their world. This is really what being a little kid is all about: you want to know what is going on out there in the big bad world, who is going to protect you, and how much you can get away with. Kids are pretty much fine with not getting away with stuff, but it has to be clear that they are outside the boundaries.
So these are the things that I strive for with my children. It's not about being strict, it's about being nice. Being inconsistent isn't nice. Then kids can't trust their world. So if you can be firm and stick to your guns, then you are doing them a huge favor. They learn to trust their world, and are confident enough to make good choices for themselves.
So why do I sometimes feel that Liam isn't getting this? Because when it comes down to it I know he might not be here. When he gets upset and cries and lies down with big, huge, crocodile tears streaming down his lovely rosy cheeks I almost always try to figure out a way to stealthily give him a little bit of what he wants so that he doesn't really know I'm letting him get his way but he will be happy again. And he is happy again. But I see these meltdowns more and more often and I know that I need to be better. I guess relative to another child it might be pretty rare (we are only talking a few times a week) but I want to be better.
The good news is he is polite in public and is polite to his teachers and doesn't melt down at school (he goes to a nursery school 2 mornings a week. Big deal for me. He loves it, of course).
So I guess in theory I am doing my job.
I always tell myself that all you can strive for is for your child to be kind and well behaved to others. When at home they will always act a little wilder and a little ruder, because they know you will always love them.
Don't I know it.
Now with Aoife the only discipline issue I am dealing with is trying to get her to wait "until the sun comes up" to have any milk. At the rate she is going I will definitely have her weaned by high school so I guess that's okay. Sigh.
I do think I am a good mom but I also know that I am really sentimental and just addicted to my kids and that often my vision is clouded by this.
Now, don't get me wrong. I am GLAD to have this clouded vision, it makes me love and appreciate them in such a unique way and it ties me to Charlotte and the gifts she left me with every day. But I still worry about the trivial things just like anyone.