I had all my children from ages 36 to 41 3/4. The only reason I stopped was that I didn't think it would have been fair for a high school kid to have a parent in their 60's. (Yes, I know that grandparents raise children, but to do it on purpose seemed self-indulgent and a bit reckless.)
Face it, lots of people have chronic health problems by that age. (I read a while back that something like 98% or 99% of Americans have chronic health problems by age 50. I am almost 50, and am one of the healthy ones, only because I consciously work on it.)
If you have a baby at 43 or later, you will virtually always be the oldest parent, and sometimes or often mistaken for the grandparent. My excellent health, taking care of my skin, and coloring my hair keep me from looking like the grandparent, but believe me, I think about it every time I enter a new crowd of moms.
If you are healthy and exercise regularly -- and I mean NO problems like blood pressure, high cholesterol, diabetes, heart disease, or obesity -- you will have the energy for this, no problem. If you have those problems, they start getting markedly worse around age 50--I see it all the time in my friends.
I just noticed that you said you are a single mom. Please don't have a child on purpose without a Dad. Children without Dads suffer long-term consequences. There's a ton of literature on that topic.