Re: DIL not wanting to live with MIL
You are right, there IS probably more to this story, but unfortunately I can't talk directly to DIL about this and therefore don't have her "side" of the story.
However, the dressing issue is simply cuz the DIL is a bit on the heavier side, and when she initially wore tight yoga pants at home all the time MIL thought it looked a bit inappropriate. Then MIL told this issue to the son, and asked the DIL to wear shalwar kameez "jab koi ghar visit karne aye" meaning only when guests come etc. The DIL doesn't actually follow this thing and still wears skinny jeans, tights, etc even though her weight is still a bit on the upper side. I do agree though that this demand of MIL is too much because girl should be able to wear whatever she wants in her own home as long as she is comfy. So yes, the MIL is more demanding in this sense. However, MIL is also the same way with both sons, always telling them to dress more "appropriate" never wear shorts etc and the sons just laugh it off and wear what they like anyways. I guess as a desi society we judge that to be OK if the sons are ignoring their mom's request for appropriate dressing but not DIL.
As far as i know, yes the MIL is more traditional, but is equally critical of these things with everyone in her life whether its her own kids or DIL, she hasn't done anything to specifically target the DIL.
The thing that really has always irked MIL is that DIL, on the first day after marriage, told everyone that she has never, and will never wash the dishes as she doesn't want her hands to become damaged or dry. So, since that day either MIL or the son wash the dishes only. Although MIL has no prob doing it herself, MIL (like a typical desi) doesn't like her sons doing housework and always gets upset if she sees HIM wash the dishes while DIL stands next to him talking and laughing.
And THIS is something where the MIL did criticize the DIL and said its not appropriate for men to do house work while u do nothing etc. After a few months and a few "convos" over this, DIL did some soul-searching, and started washing the dishes in the dishwasher occasionally (weekends only, if she didnt have to study). Now the DIL always makes this a big thing that she has changed herself soo much for the family and even started helping out with the housework etc. and she should be appreciated for it.
The DIL once also made an issue when son was eating MIL's food and complimented it many many times in one sitting. The DIL made the same dish over the weekend and son didn't compliment it but just once. DIL then told son to no longer compliment MIL's cooking so much as it makes her feel bad. This has been admitted by DIL in a convo with me.
It sounds like you could be one of the main problems...as you seem to be interfering and judging a hell of a lot!