There hasn’t been any such qualified research on it as of yet, but it won’t be surprising if that happens to be true. In fact, I personally believe, working mothers are best at time management and they know how to be super productive all the time.
When a mother leaves a child at home, she knows what exactly she expects as a trade-off ! You would barely see a working mother for a late night office party or major office gossip. She would be driven and focused because she understands that there are no options.
Take this example. If you continue to arm a person with more and more high-stakes responsibilities, that person would become even more efficient and time-effective. Similarly, working mothers have countless responsibilities on their shoulders. For many of them, slacking isn’t even an option. So, they have to work hard, juggle every task efficiently and be more productive. There’s no other way.
On the other hand, lacking any big responsibility, one person will always procrastinate, be unproductive and usually be late in delivering on projects.
So yes, even when I cannot back my claim with any study or research, I do believe working mothers are best at managing time and being efficient at their work.