I am in the same position as you.
You are not being mean, you have just reached the end of your tether since you’re being made to feel uncomfortable in your own house (which is unacceptable!!) you do not need that negativity around you and your DP should understand this. To some extent I agree that your DP should be dealing with this but if this is an issue , take matters into your own hand by explaining to your MIL. This maybe easier said than done depending if you DP is a mummy’s boy, I’m lucky in the sense that my DP is not.
My pessimistic MIL lives 1.5 hr away and travels via public transport despite being able to drive, so she expects to stay over, being chauffeured around and like you, expects to be waited on. This was the case even 2- 3 weeks postpartum with our first child and when we explained that she couldn’t stay when the baby arrived , she threw in the waterworks.
LO still wakes up for feedings in the middle of the night and going through separation anxiety, so I’m getting up multiple times to attend to LOs needs and naturally I want minimal distraction so that LO can get back to sleep.
I should mention here that the MIL stays up until early hours of the morning watching TV in her own house, but she also thinks it’s ok to do that at my house, even after my LO was born. I find this is extremely selfish and inconsiderate.
Can I just add that she has never once offered to help with the baby when she has stayed over- not even one nappy change!
I also find the bath thing weird too, my MIL does this and I explained to my DP that I would never dream to soak in someone else’s bathtub if I was their guest … it’s just weird.
Anyhow, it has gotten to a stage where the MIL invites herself to stay using my LO as an excuse to come down more often as she lives alone and divorced. She is constantly badgering DP for his attention. She has never messaged myself to check on LO/ updates on milestones etc- again I find this weird because if she really wanted to know, she has my number and has previously messaged me in the past about other things.
Seeing as my DP didn’t want to deal with upsetting her by saying it’s not OK to invite herself down and assume it’s OK to stay with us. I have now nipped this in the bud by being honest with MIL that it is difficult having guests in the house with LO around, especially with the night wakings and that I am sure she can understand - after all, she’s gone through the motherhood too!
Now, before I said this to her I checked that my DP was ok with this since I didn’t need this to affect my marriage.
Sorry for the long post, but I completely understand what you are going / have been through. So now that your LO has arrived, you have to do what is best for you and your new family.
(BTW, my MIL has not replied to my message after reading it, but she has complained about me to my DP. Again, this is the least of my worries and atleast I am not being made to feel uncomfortable in my own house anymore).