OP here. Sorry I haven't been able to reply in a while. Just to answer some questions:
Yes, the issue here is my mother, not my mother-in-law, and while I do agree that DH does get on my case from time to time about his opinion that I'm "too easy" on my mom, deep-down he has a point, and I feel like it puts me in a tough spot. Mainly because, where my mom is concerned, I tend to feel that trying to get her to respect my ways and accommodate is pretty much pointless (it has never worked), so I've just given up over time, yet I'll complain to him, or he'll see things that he knows bugs me and wonders why I don't do something about it. As I try to explain to him, with my mom, things are not as straightforward as they are with his own mom, who is willing to bend over backwards to respect our wishes.
Someone asked about the relationship with my mom and her mom, which is a great question and a good reminder to me that I should also consider this when feeling frustrated. From the little she has told me, my grandmother, though completely invested on an emotional level in my life, apparently did not help my mom with any "stuff" when taking care of my sister and I. So, my mom often tells me that she had to pack so much to bring over to her house because grandma had nothing there for us. Material things are very important to my mom. She has told me on several occasions (out of context from the situations I am posting about) that she wants to keep things at her house and have things handy so that I don't need to feel burdened when I do bring DS over.
At her house, that's great...and I do appreciate this and where it comes from (even though, the type of person I am, I'd rather pack up all of my stuff knowing it is the stuff I am comfortable with and it is what I picked out! But that's just me). But at my house, it is irritating because I have his stuff there...so I don't see why she brings wipes, or packs her own food for him, or brings her own outfits for him to wear, other than the fact that it is, as I mentioned in a previous response, her way of making things more of HER OWN experience...doing things the way she wants so she can be happier. That is the only thing I can pinpoint as to why she does this, knowing how she is.
I would like to clarify that DH really isn't an issue here. I think the "contention" I mentioned that comes about from him getting on my case and us disagreeing about all this is that, deep-down I agree with what he's saying, but I don't know how to change things, and I get defensive because I feel stuck. Hence, why I'm posting here for suggestions.
I do think there is something to be said about not putting my mom's needs first. I do have some level of resentment towards my mom despite my love for her; it is hard to always have to accommodate her needs but not get much of it back. Yes, I am grateful she helps me, is in my son's life, but no matter what, things are and always will be on her terms and everything has to be convenient for her. As I've said, she means well, but the issue at hand is that there are things she does that makes it really difficult for me to feel that I have the authority I want over my son's wellbeing.