Even if it's been six weeks, even if your partner's been told she can go ahead and have sex again, she may resist. She may be afraid of pain, she may need more time, she may just be tired. A few well-placed compliments won't hurt either. If she's breastfeeding, her body is constantly in demand, and even if she's not, taking care of a newborn is an intensely physical job. Finally, don't forget that during the recent miracle of your baby's birth, your partner spent several hours with the most private parts of her body on display to a roomful of nurses, midwives, and doctors.
Sex can seem like one more demand, meeting one more person's needs.
As your partner adjusts to a whole new role, she may have little energy left at the moment for physical loving. But that doesn't mean she loves you any less. In fact, many couples find the period after childbirth very romantic, if not very sexual. In a sense, she's not the same person you drove to the hospital a month or two ago. She's still your wife, but now she's also a mother.