Hi, T.,
My husband and I are 43. Our first live child was born when I was 40 1/2; my second was born six weeks before I turned 42.
Life with two kids is noticeably different than life with one. I have a hard time getting my kids to sleep at the same time. Consequently, I feel as though I virtually never get a full night's sleep now that I have two. Feeding, dressing after a bath, pushing in a stroller, putting in a car, scheduling medical appointments and classes are more challenging experiences with two kids than with one. Swimming lessons are out of the question now because each child must be accompanied by one adult and my husband works out of town a total of half the year. (His schedule as a musician/roadie is inconsistent and often changes on a moment' notice.)
I try to stay in shape (exercise regularly and try to maintain a very healthy diet). Nonetheless, I don't think that I am as energetic as I was when I was 23. Some people say that age is just a number. It may be a number, but it is a meaningful number. Although I can take great care of myself, I like everyone else, am more prone to debilitating physical problems than I was ten or twenty years ago. This statement is not an ageist remark; it is a fact. Some people, in justifying having kids later in life, say that you never know when you will die and that young people die, too. While those statements are true, the older we are the more likely that we will die, or become physically disabled, esp. by heart attack or stroke, in the next moment.
I was really surprised to find myself pregnant at 41 without trying, especially considering how much my husband and I went through to conceive and carry to term my first live child. I am grateful to have two children. However, I think that my elder son, my husband and I probably would have been just as happy if we were a family of three instead of four.
Before taking the plunge, carefully consider your financial situation. Each child costs, by most people's standard when calculated honestly and accurately, a significant amount of money. Based on a rough estimate of my family's expenses, the cost of care for a second child is approx. 80% of the cost of care for the first. My second son can wear the clothes that my first has outgrown, but other than that, my husband and I pay twice as much for two kids and we did for one. Before my husband and I conceived our second child, we thought that we might be able to fund a large part of our offspring's college education. Now, I don't think that that is possible, even if I work full-time and we continue to be frugal. I will probably have to work longer (more years) than I would had my husband and I had only one child.
Also, be honest with yourself about your energy level. Everyone is different. Don't be swayed by people on one extreme who tell you that you will automatically find the energy (or money) to raise another child well or people on the other extreme that you absolutely should not do it. They, for the most part if at all, won't live with your decision.
Try to decide BEFORE conceiving how comfortable you are with the possibility that your offspring may have genetic problems, e.g. Down Syndrome and what you will do if your offspring shows signs in utero of having this type of problem/issue. The odds are that your child will not, but they are much higher on average than the odds in cases where parents are in their twenties. My husband and I were comfortable taking the chance and decided that we would not abort a deformed, disabled fetus if I became pregnant with one. Neither one of our kids seems to have any significant deformities or disabilities.
I would not recommend creating a sibling just to keep your current child company. Although my kids seem to get along well now, I cannot assume that they always will. The siblings on one side of my family get along quite well; the siblings on the other fight over anything and everything. Sometimes, friends make better companions than siblings. By the way, my kids have very different personalities and interests. One cannot reasonably assume that a subsequent child will be just like the first-born.
If your heart is really into having another child and you think that you can financially and physically handle another one, then it does not seem unreasonable to try to have another one.
Good luck in your decision.
Lynne E