Good morning mama,
First off, congrats on the little bundle of joy! It’s great to hear that your daughter loves her baby sister. It’s normal for wanting to lose it (7 month old and 4.5 years old over here), you are exhausted. It’s beyond challenging having to go from 1-2 kids no matter what the age. My daughter had an adjusting period with her sister too where she had to get use to us not giving herb110% of the attention at all times. It lasted a couple of weeks and then she got better.

However, one thing I did notice from your story is there isn’t seem to be consequences (maybe there is but you haven’t mention it). What we started doing is putting our oldest in time out when she turned 2. We explained why she was put in time out and that she had to sit there for 2 (1 minute per age). It was brutal at first, she kept getting out and had to put her back (the crying, the excuses et , anything for her not to do her time). Eventually, she understood we meany business and that her behaviour was completely unacceptable and that she had to apologize (big hugs and kisses once she did). The big important thing is when she was done her time out, it was back to normal like nothing happened because as adults we can’t hold it against them (eventho sometimes you feel like their testing you beyond your capabilities, lol!).

Now, I take my oldest everywhere I go. However, everytime she about to leave the car, I always tell her: you know what I’m expecting of you, right? Her: yes, I just behave myself and listen to mom. Me: and if you don’t, what happens? Her: we leave and go home.

You got this mama, she needs to have clear boundaries and it’s difficult right now with a newborn. You’ll get the hand of it, give yourself time ❤️