Never say to a new mother "remember to take some time for yourself." Just don't do it. Stuff a sock in your mouth if you have to, but keep the words to yourself.
    I went to a baby shower recently where a mother of two gave the new mother a rousing devotional talk. The well-meaning experienced mother, who should surely have known better, resorted to this tired and useless theme. Finally, she said, "take time for yourself. It will make you a better mother and a better wife." (Oh, second only to my distaste for advice to take time for yourself is my abhorrence of the phrase "put your husband first." Like that's actually possible when you have a screaming baby in your arms.)
    Let's give new mothers a break. First, imagine what they actually hear when we say this vicious little phrase.
    Here's what a new mother's life is like: all of a sudden she has an infant on her hands who absorbs every bit of her attention and love and care. She is delighted that he has arrived, but he seems to need something different every two minutes. He cries and she has to comfort him. Then he blows out a diaper and she has to clean up a mess while he cries and she feels as though she should be comforting him. She remembers that she has nothing in the house to cook for dinner and feels as though she should be grocery shopping instead of cleaning up soiled clothing (or bedding, or furniture, or...) but first she's going to have to comfort him because she really should be doing that, too, along with the laundry from yesterday's accidents. Time gets past her and she realizes it's too late to go shopping and she really should be cooking or at least coming up with a plan for cooking when there's nothing in the house but she's feeding the baby right now and at least he's not crying. And she knows she should have found time this morning to change out of her nightgown and brush her teeth. And she should be taking a nap right now because the baby woke up twenty times the night before, but there's no time.  She has a nagging suspicion that she is dreadfully inadequate and that other people, if they knew, would make fun of her. 
    To advise this harried, pathetic person to "take time for herself" is to confirm her fear that there is something else she is not doing right, and that she is a bad mother. (To tell her that she should put her husband first is to tell her that she's a bad wife.) A very reasonable answer for her to give would be something honest like "I don't need a blooming bubble bath, I need a week off!"  But most of the new mothers respond instead with a sickly smile and a gnawing anxiety that their well-wisher knows the real truth about them.
    I have three children, and sometimes people inquire of me "are you managing to take time for yourself, though?" I think about my day so far. At a very early hour of the morning, the four-year-old came into my room. "Mommy, I had a nightmare. Can I sleep here? she says. I'm too tired to care, so I grunt and she lies down. She tosses and bops me in the face.  
    So I think: okay, I'm already awake, so I'll get up and have some time to get ready for the day before they wake up. I've been up three minutes, and just brushed my teeth when the baby wakes up and wants to nurse. With a last glance at my morning routine list, which is posted optimistically on the wall, I take care of that. By the time she's finished, the six-year-old is up and wants breakfast. The children play tag-team on Mommy's attention for the rest of the day, broken only by the trips to school, with one need or crisis after another. Breaking up fist fights, rescuing the baby from her climbing adventures, picking up dangerous objects that the older ones left on the floor for the little one to find, and trying to do housework fill up the few remaining gaps in the day.   
    So when someone asks if I manage to take time for myself, I imagine what would happen if I locked the bathroom door while the four-year-old was experimenting with shish kebabs on her older brother, and the baby was discovering the fascinating contents of my purse. Let's just say it wouldn't be very stress-relieving for me.
    Really, what is the point of saying this depressing little phrase? Let's break it down to its depressing parts. The first word is TAKE. A mother does not take. She is asked to learn how to give, and give and give and give until she thinks she has nothing left to give, and then give some more. Taking is a foreign concept to a mother. A mother would be happy to RECEIVE, but she is in a poor position to TAKE anything.

    Next, SOME TIME. How much is some time? Ten seconds? That might be possible. But no mother wants ten seconds. She wants an hour, two hours, or two months. "Some time" also sounds like a vague date in the future. To a mother's brain, focused on the now of crisis, a vague date is equivalent to never. How much time, and when, is what she is wondering when she hears this.

     FOR YOURSELF. This is the worst part. Yourself is not the focus when you are a new mother. Yourself is of no importance to anyone, except maybe the past self you dimly remember. Infants don't even really know you exist as a separate being, and young children have a hard time seeing you as human. FOR YOURSELF is a phrase from another planet, and it doesn't make sense in your frame of reference. It turns the whole phrase into gibberish, and makes you chuck it out in exasperation, because you don't have time to understand a new language right now.

     So what could we say that would be helpful to new mothers? How about: "Surprise! I'm here to take care of the children while you go take a shower right now." Or, I'm coming over to clean your kitchen since you probably haven't had time to do it yet." (Or maybe the bathrooms, if you're a really good friend.) If you really believe she needs some time for herself, take action to make it happen. Buy her two movie theater tickets (non-refundable) and offer to babysit while she goes out with her husband for the evening. Fold her laundry. Take the baby for a walk. Be goofy and fun with the baby or kids while you’re visiting. Make her take a nap or go to her room and read a good book instead of entertaining you while she's trying to take care of the baby AND do the housework.

     Talk is cheap, so the rule of thumb is this: if you aren't willing to do something about it, don't mention it. If you are, though, you will become an angel to someone who really needs one.