It took an entire year for my body to feel like mine again after I had Aillidh. I have had 4 surgeries on my knees, including a ligament graft, and like you, my joints were week for about 6 months afterwards. Once I went back to weights and Pilates, however, my leg muscles built up again and the weakness either went away on its own or the muscle development made me not notice it a/more.
Like Kellie, I was 32 when I had my first child.