I’m surprised she wants to get pregnant with another baby while your new baby is only 4 months old. Is it because she is advanced in age? That would make sense to me. Is it because she wants them to be very close in age?

Good reasons aside, if you do not want another, then don’t consent to have another. I am glad she is asking you for consent and not having an ‘accident’.

We had two kids 23 months apart. My h felt that was all he wanted, though I would have like to have a third. I was fine and respected his choice. But, when they were 7 and 5, I asked again if we could try to have a third, he agreed to try, and we got pregnant. He was happy with having the three. Tbh, the two older ones really wanted a baby when they were younger, but at the ages we had our third, they said they’d rather not. But they were happy with him and loved him, and they all got along.