Thanks for all the responses. I do agree completely that "fair" and "even" are two completely different things, especially when it comes to little things. Like the swim goggles, underwear, or even spending the same amount at xmas for all the kids. I probably didn't name the thread properly. I had such a hard time trying to figure out exactly how I feel on the subject.
I think it was a mixture of hormones and holding a grudge at my MIL for an earlier conversation when she said that the amount of kids DH and I want are "too many" and I should only have two or three. After thinking of this subject for a while I think I projected that conversation into my reaction to the baby blanket thinking "well, you are only going to make things for the first 2 kids because that's all you approve of." I'm sure that's not going to be the case, and she will approve/love all my hypothetical children, but that was at the root of what I was feeling.
Even if that was to be the case I suppose it doesn't matter as long as my kids know on some level that I love them and stuff is really just stuff. It's completely logical to think that if I worry about material possesions between them being fair that is putting emphasis on something that in the grander scheme of things doesn't matter. It could completely back-fire and turn them into materialist people.
Also I do agree that it depends on the kid's wants/needs. My nephew's only interest is minecraft. He would be happy doing nothing all day except play that game. My niece on the other hand wants to play sports, do drama, ballet, and recently asked if she can join a gymnastics team. These activities are WAAAAYYY more expensive and time consuming but that's what she wants. My sister forced my nephew to play soccer so that he would "do something not computer related."
I think you have a good handle on this. Good luck!