If people are keeping track, even subconsciously, they have already missed the whole point of Christmas. The problem here has nothing to do with money.
It is not the receiver that is blessed on Christmas day, but the giver.
How about this -
1st daughter - gifts purchased with love
2nd daughter - gifts purchased with love
Husband - gifts purchased with love
Child 1 - gifts purchased with love
Child 2 - gifts purchased with love
Child 3 - gifts purchased with love
Child 4 - gifts purchased with love
Child 5 - gifts purchased with love
Child 6 - gifts purchased with love
Plenty of love - isn't that what it is all about?
I honestly get what you are saying and I don't disagree with you but I guess I do, in a way.

Clear as mud, right?
I have two kids. I don't sit there and add every dime up that I spend on them. I am not all about making it even. However, I do have a minimum that I spend. I do not have a maximum. One year, my DD needed a new laptop so she got that plus plenty of other expensive things. DS didn't want or need anything that was that expensive but I did make sure to spend the minimum on him. This year, it is the complete opposite. I went WAY over my minimum with DS and just hit the minimum with DD. It is based solely on what they want. They are gifts that were purchased with love. So, this is the part where I agree with you!
However........there are exceptions. My mom chooses to give cash. She has done this for years now. I keep track of her finances so I happen to know how much she gives everyone. If my mom chose to give my DH $100 and only gave my sister's DH $25, that would certainly say something. Again, her money and she can do what she wants but playing favorites is never a good thing in a family.
Another example. I have three separate families that I buy for. I am not particularly close to them since they all live in different states. My budget is $50. Thanks to some great online deals, I only spent $30 each on two of the families and was able to get them around $65 worth of stuff. The other family has much younger kids and I didn't find any deals so I spent the $50 I had planned. I don't see anything wrong with that. It is the thought that counts. I put effort into it and I can't imagine anyone complaining or feeling slighted. If they did, I would think they are missing the whole meaning.
Personally, I think my mom should only give money to the grandkids and great-grandkids. I think giving money to her grown kids and our spouses is a waste and we have all tried to convince her for years to stop. She insists so it is what it is. However, if she chooses to go this route, I do think it makes sense to give a fairly equal amount.