Aiyo, I really feel you on this, please don't suffer in silence because you're definitely not alone in this! My neighbour also had the same thing after her second baby, knees so weak she had to hold the wall just to get up from the floor, and her gynae explained it's actually quite common after birth because of all the hormones that loosen your joints during pregnancy, and they take time to settle back. Someone in my mum WhatsApp group mentioned that her physio told her it's normal but, and this is the important part, "normal doesn't mean you just have to tahan it," so she went for postnatal physiotherapy and said it really helped with the knee weakness and even her hip stiffness. My friend who gave birth around the same time as you went to a women's health physio specialist and they gave her specific exercises to strengthen the muscles around the knee so they're not so wobbly, and she said within a few weeks she could already squat down to bathe her baby without pain. Of course lah every mummy's body is different, so do check with your own doctor or an ortho/physio specialist to make sure nothing else is going on, especially since you mentioned it's quite bad! You got this, mama, hang in there!
I experienced something similar after giving birth too 😭 My knees felt weak and squatting was so painful for a few months. My doctor said hormones, joint laxity, and carrying baby all day can contribute. It did improve gradually, but if it’s severe or affecting daily activities, I would get it checked just to be safe. ❤️